Apologies for the re-post, it was the only way to save the post and comments with the correct tags after the Blogger meltdown the other day!
I've been accumulating a lot of mother-y links lately, thought I would share. First two Mother's Day columns that remind us that we shouldn't just put Mom on a pedestal and give her some chocolate one day a year, but think in a more systematic way about the oppression of women and children worldwide. Read this one by Esther Cepeda, and this one by Nicholas Kristof.
Fertility
Women see Georgia O'Keefe art as erotic around ovulation. I'm not sure this really qualifies as evolutionary psychology, or needs that framework to understand that libido is higher near ovulation, which would increase the chances one would find erotic art extra erotic at that time.
Birth
Chimps give birth like humans. Very cool. I guess we didn't notice until now because they are so solitary when they birth?
Cesarean sections are a major factor in maternal death. I don't like how this article seems to blame the mother, given the way interventions seem to shunt many women towards C-sections whether they want one or not. But there are certainly many factors to consider in this issue, including the mother's past health and the kinds of protocols used at the location where she is giving birth.
Cutting the cord too soon. This is an interesting piece in Time about the timing of cord clamping and its impact on respiratory issues in infants. Many birth centers and hospitals are advocating for a later time to clamp the cord for this and other reasons.
Mothering of all kinds
Hope for teenage mothers. This was a great story about a great program to help teen mothers have more success in school and beyond.
The amount of time a woman breastfeeds is related to her race and income. Not surprising, given that lactation support services are probably harder to come by, and that women who must earn an income can't necessarily afford to go without pay for twelve weeks (that is the minimum maternity leave we get in the US, based on the Family Medical Leave Act, and most places give only that minimum). Even those women who do manage to get into a rhythm with breastfeeding lose it when they return to work, not just because of those short twelve weeks, but because few employers have workplaces set up for pumping.
Amy Poehler's acceptance speech at the Time 100. She discusses the many other women (dare I say allomothers?) who support her as she raises her children and has a career. I may have teared up a little. Okay, I shut my office door and cried.
What measles vaccine refusal really costs. This is something parents should care about.
A hilarious account from a father about all the things you need to worry about -- and expect to be judged upon -- when having a child.
Finally, while this went around the interwebs when Dr. Isis wrote it the first time, re-read her AGORA post about why it's all right to not be your mother.
Miscellaneous ladybusiness
The enduring gender gap in pay. Sigh.
Michele Bachelet should be everyone's hero, if what I read in this story is any indication.
We can no longer escape the reality that BPAs (and other associated bisphenols, which unfortunately are what are being replaced in plastics that claim to be BPA-free) are endocrine disruptors that have negative consequences for health. Well, unless you're Coca Cola. Then you are going to put your fingers in your ears and go "lalala!"
A lovely post on feminist reactions to street harassment. Another, very powerful read: kill me or leave me alone.
An important read about the use of language in journalistic storytelling, and the sexist way the New York Times originally covered the brutal gang rape of a little girl.
Historic STD posters. Were some sexist? Of course. But it only makes me want one for my office more, if for its ironic value.
Showing posts with label pregnancy. Show all posts
Showing posts with label pregnancy. Show all posts
Monday, June 6, 2011
Tuesday, May 17, 2011
Do girls steal some of their mother’s beauty? Sex bias in parental investment
Sons and daughters and differential parental investment
One of my favorite rhetorical tricks is asking my students a question that has an obvious answer based on cultural expectations, but is wrong. So every year, when I start to teach my students about parental investment, I ask:
So then I show them this:
Here is a graph of maternal longevity based on the number of sons or daughters they have. This data was based on a historical population from Finland from 1640-1870 using church records (Helle et al 2002). As you can see, the more sons mothers bear, the shorter their lifespans. You see the opposite for daughters. So sons have a negative impact, and daughters have a positive impact. This same trend has been found in records from a Flemish village (van de Putte et al 2003, 2004), where sons negatively impact lifespan but not daughters. Interestingly, data from church records from the field site where I work in rural Poland provides a slightly different picture: every offspring of either sex reduced lifespan by about 95 weeks (Jasienska et al 2006).
Once students see these graphs, they quickly realize what is going on. Generally speaking, girls help mothers more at home in terms of chores and alloparenting. And in many cultures, particularly the historical ones studied so far, sons are costly because parents invest more in them, to help launch their own families. Daughters, not so much. In the Polish population, there may be other factors where daughter investment is important, or it is just costly to have so many offspring and you have maternal depletion regardless of daughter help.
Sex bias in parental investment is an important part of understanding both the biology and culture of parenting, and the developmental trajectories of children. The Trivers-Willard hypothesis, which has been tested many times in humans and animals, suggests that parents should invest more in sons when conditions are good, and more in daughters when conditions are bad. That is, when you have lots of resource you should put it towards a son in order to increase the chances he will have high reproductive success, since his is assumed to be more variable and high effort could lead to high reward. But in periods of low resource, daughters are a good bet because they are more likely to have at least some reproductive success no matter what.
Of course, differential investment based on resources is further conflated in humans due to culture and, I would contend, our almost universal favor for patriarchy (Smuts 1995). Here is an image of an Indian family waiting at a clinic. There is a mother, an older son, and a twin boy and girl. Notice the extreme difference in health between the infant boy and girl – they are twins, yet the infant girl is emaciated. This is because in this population sons are always fed and cared for first, and whatever is left over, if there’s anything, is given to daughters.
So, parental investment can have real effects on the parent in terms of lifespan, and perhaps also their own future reproductive capabilities. Further, the conditions under which you may have children can vary, but how much a parent chooses to invest in their children varies too.
The piece of this that may be toughest to parse out, particularly in humans, is how the condition of the mother (or parents) can vary, and how that variation impacts the sex ratio of their children. In some species, like red deer, it is easier to imagine a mechanism: these animals have diapause, a period where their embryos are dormant until it is a good time to gestate and bear them. It is easier to insert some kind of selection process into a period where several embryos are all “frozen” and sex has been determined. But what about humans that produce singletons and invest huge, overlapping amounts of support to their children over decades? How would a sex bias based on maternal condition operate? And is there anything the offspring can do about it?
Changes in maternal breast size during pregnancy
It turns out that measurements as easy as stepping on a scale, and knowing your bra size, can begin to unpack the answer. First, a confession: I consider the author of this paper Andrzej Galbarczyk more than a colleague, but a friend. Andrzej is the graduate student who oversaw my Polish field site last season (Mogielica Human Ecology Study Site, director Dr. Grazyna Jasienska). He has translated consent forms and surveys for me and we’ve had many valuable and important conversations about my fieldwork. He is a smart, kind and thoughtful person and scholar. So, I let him see an early draft of this post to make sure I understood his point of view.
Galbarczyk performed an internet survey in Poland with 120 women, where he asked them to report their pre-pregnancy weight and bra size, their bra size directly after giving birth, and the sex of their offspring. He found two notable differences in these women: mothers of daughters weighed less before pregnancy, but had a greater changes in breast size during pregnancy.
The evidence about maternal pre-pregnancy weight is consistent with the Trivers-Willard hypothesis, as mothers who had sons were more likely to be heavier, and thus have more resource to invest. The second significant difference, that mothers with daughters had larger breasts after pregnancy, seems could be argued either way: Galbarczyk argues that it supports Trivers-Willard because mothers of sons could have been devoting more resource to growing their offspring rather than their breasts.
In other animals and primates particularly, mothers of male infants produce more energy-dense milk, yet mothers of female infants may produce a greater quantity of milk (Hinde 2009). And breast size is a pretty noisy signal of milk quality or quantity. So, what is the meaning of this difference in breast size?
Adaptation or physiological inevitability?
Galbarczyk suggests the difference is related to the evolutionary underpinnings of human female breasts. Women develop breasts around puberty, and though they certainly change in size and shape over time, keep them their whole lives. Other animals develop their mammary glands only shortly before lactating and then they regress again. Many contend that human breasts are an honest signal of fertility. This is at least partially confirmed by the correlation between breast size and estradiol concentrations (Jasienska et al 2006).
Galbarczyk thinks that the larger breasts seen in postpartum mothers to daughters may be a way to attract a mate for parental care. Perhaps this would help where she has given birth to the less-favored sex and needs to really convince him to participate; this could be a signal from the mother or the female fetus. Or maybe by appearing more attractive, she can have another reproductive opportunity, which would give her a chance to have a son.
You all know how I feel about evolutionary storytelling. In certain ways I do find this particular argument compelling, from the perspective of the Trivers-Willard hypothesis. But the evidence for the adaptive scenario around breast size is circumstantial.
Also, I don’t want this story to detract from some very interesting data: remember that Galbarczyk found that in this population, mothers of daughters weigh less before pregnancy, and develop larger breasts afterwards. Very cool. So perhaps we should consider a mechanistic, rather than adaptive explanation?
I have two thoughts about this, both related to androgens (androgens are the class of hormone that testosterone falls under). First, I wonder if there is an effect of fetal androgens from a male fetus on breast size. If so, mothers of daughters would have larger breasts simply because they aren’t having their breast tissue growth or density suppressed by androgens. It could simply be physiology that doesn’t have adaptive meaning.
Second, the mothers of sons were heavier before pregnancy. Heavier individuals tend to have higher circulating insulin levels, and the ovary can respond to higher insulin by producing more androgens (Poretsky 1991, Dimitrakakis et al 2004). So you could have a suppressive effect on breast size from that avenue as well. You don’t need an adaptive scenario for either of these mechanisms, just a consequence of how hormones work.
I would love to see Galbarczyk or someone else follow up on these thought-provoking results by measuring women, rather than relying on self-report, and by measuring their estradiol, progesterone and androgens. Understanding the different factors and motivations that lead to sex differential investment and outcome is a great field of study, and this work gets us thinking in a new direction.
References
Dimitrakakis C, Jones RA, Liu A, & Bondy CA (2004). Breast cancer incidence in postmenopausal women using testosterone in addition to usual hormone therapy. Menopause (New York, N.Y.), 11 (5), 531-5 PMID: 15356405
Galbarczyk A (2011). Unexpected changes in maternal breast size during pregnancy in relation to infant sex: An evolutionary interpretation. American journal of human biology : the official journal of the Human Biology Council PMID: 21544894
Helle, S. (2002). Sons Reduced Maternal Longevity in Preindustrial Humans Science, 296 (5570), 1085-1085 DOI: 10.1126/science.1070106
Hinde K (2009). Richer milk for sons but more milk for daughters: Sex-biased investment during lactation varies with maternal life history in rhesus macaques. American journal of human biology : the official journal of the Human Biology Council, 21 (4), 512-9 PMID: 19384860
Hrdy, S. (1990). Sex bias in nature and in history: A late 1980s reexamination of the “biological origins” argument American Journal of Physical Anthropology, 33 (S11), 25-37 DOI: 10.1002/ajpa.1330330504
Jasienska G, Nenko I, & Jasienski M (2006). Daughters increase longevity of fathers, but daughters and sons equally reduce longevity of mothers. American journal of human biology : the official journal of the Human Biology Council, 18 (3), 422-5 PMID: 16634019
Poretsky L, Seto-Young D, Shrestha A, Dhillon S, Mirjany M, Liu HC, Yih MC, & Rosenwaks Z (2001). Phosphatidyl-inositol-3 kinase-independent insulin action pathway(s) in the human ovary. The Journal of clinical endocrinology and metabolism, 86 (7), 3115-9 PMID: 11443175
One of my favorite rhetorical tricks is asking my students a question that has an obvious answer based on cultural expectations, but is wrong. So every year, when I start to teach my students about parental investment, I ask:
Who is harder to raise, sons or daughters?I’ve asked by a show of hands and with iClickers, over the years, and the room of 750 is almost unanimous: daughters are harder to raise. So, then I get off the stage and walk around a bit. What do you mean by that? I ask.
Girls cause more gray hairs.And of course, there is always the saying that girls steal some of their mother’s beauty.
Girls cause more trouble when they start to like boys.
Girls are more work, and cost more money, since they shop all the time.
Girls talk back more.
So then I show them this:
 |
| From Helle et al 2002. |
 |
| From Jasienska et al 2006. |
Sex bias in parental investment is an important part of understanding both the biology and culture of parenting, and the developmental trajectories of children. The Trivers-Willard hypothesis, which has been tested many times in humans and animals, suggests that parents should invest more in sons when conditions are good, and more in daughters when conditions are bad. That is, when you have lots of resource you should put it towards a son in order to increase the chances he will have high reproductive success, since his is assumed to be more variable and high effort could lead to high reward. But in periods of low resource, daughters are a good bet because they are more likely to have at least some reproductive success no matter what.
 |
| From Hrdy 1990. |
So, parental investment can have real effects on the parent in terms of lifespan, and perhaps also their own future reproductive capabilities. Further, the conditions under which you may have children can vary, but how much a parent chooses to invest in their children varies too.
The piece of this that may be toughest to parse out, particularly in humans, is how the condition of the mother (or parents) can vary, and how that variation impacts the sex ratio of their children. In some species, like red deer, it is easier to imagine a mechanism: these animals have diapause, a period where their embryos are dormant until it is a good time to gestate and bear them. It is easier to insert some kind of selection process into a period where several embryos are all “frozen” and sex has been determined. But what about humans that produce singletons and invest huge, overlapping amounts of support to their children over decades? How would a sex bias based on maternal condition operate? And is there anything the offspring can do about it?
Changes in maternal breast size during pregnancy
It turns out that measurements as easy as stepping on a scale, and knowing your bra size, can begin to unpack the answer. First, a confession: I consider the author of this paper Andrzej Galbarczyk more than a colleague, but a friend. Andrzej is the graduate student who oversaw my Polish field site last season (Mogielica Human Ecology Study Site, director Dr. Grazyna Jasienska). He has translated consent forms and surveys for me and we’ve had many valuable and important conversations about my fieldwork. He is a smart, kind and thoughtful person and scholar. So, I let him see an early draft of this post to make sure I understood his point of view.
Galbarczyk performed an internet survey in Poland with 120 women, where he asked them to report their pre-pregnancy weight and bra size, their bra size directly after giving birth, and the sex of their offspring. He found two notable differences in these women: mothers of daughters weighed less before pregnancy, but had a greater changes in breast size during pregnancy.
The evidence about maternal pre-pregnancy weight is consistent with the Trivers-Willard hypothesis, as mothers who had sons were more likely to be heavier, and thus have more resource to invest. The second significant difference, that mothers with daughters had larger breasts after pregnancy, seems could be argued either way: Galbarczyk argues that it supports Trivers-Willard because mothers of sons could have been devoting more resource to growing their offspring rather than their breasts.
In other animals and primates particularly, mothers of male infants produce more energy-dense milk, yet mothers of female infants may produce a greater quantity of milk (Hinde 2009). And breast size is a pretty noisy signal of milk quality or quantity. So, what is the meaning of this difference in breast size?
Adaptation or physiological inevitability?
Galbarczyk suggests the difference is related to the evolutionary underpinnings of human female breasts. Women develop breasts around puberty, and though they certainly change in size and shape over time, keep them their whole lives. Other animals develop their mammary glands only shortly before lactating and then they regress again. Many contend that human breasts are an honest signal of fertility. This is at least partially confirmed by the correlation between breast size and estradiol concentrations (Jasienska et al 2006).
Galbarczyk thinks that the larger breasts seen in postpartum mothers to daughters may be a way to attract a mate for parental care. Perhaps this would help where she has given birth to the less-favored sex and needs to really convince him to participate; this could be a signal from the mother or the female fetus. Or maybe by appearing more attractive, she can have another reproductive opportunity, which would give her a chance to have a son.
You all know how I feel about evolutionary storytelling. In certain ways I do find this particular argument compelling, from the perspective of the Trivers-Willard hypothesis. But the evidence for the adaptive scenario around breast size is circumstantial.
Also, I don’t want this story to detract from some very interesting data: remember that Galbarczyk found that in this population, mothers of daughters weigh less before pregnancy, and develop larger breasts afterwards. Very cool. So perhaps we should consider a mechanistic, rather than adaptive explanation?
I have two thoughts about this, both related to androgens (androgens are the class of hormone that testosterone falls under). First, I wonder if there is an effect of fetal androgens from a male fetus on breast size. If so, mothers of daughters would have larger breasts simply because they aren’t having their breast tissue growth or density suppressed by androgens. It could simply be physiology that doesn’t have adaptive meaning.
Second, the mothers of sons were heavier before pregnancy. Heavier individuals tend to have higher circulating insulin levels, and the ovary can respond to higher insulin by producing more androgens (Poretsky 1991, Dimitrakakis et al 2004). So you could have a suppressive effect on breast size from that avenue as well. You don’t need an adaptive scenario for either of these mechanisms, just a consequence of how hormones work.
I would love to see Galbarczyk or someone else follow up on these thought-provoking results by measuring women, rather than relying on self-report, and by measuring their estradiol, progesterone and androgens. Understanding the different factors and motivations that lead to sex differential investment and outcome is a great field of study, and this work gets us thinking in a new direction.
References
Dimitrakakis C, Jones RA, Liu A, & Bondy CA (2004). Breast cancer incidence in postmenopausal women using testosterone in addition to usual hormone therapy. Menopause (New York, N.Y.), 11 (5), 531-5 PMID: 15356405
Galbarczyk A (2011). Unexpected changes in maternal breast size during pregnancy in relation to infant sex: An evolutionary interpretation. American journal of human biology : the official journal of the Human Biology Council PMID: 21544894
Helle, S. (2002). Sons Reduced Maternal Longevity in Preindustrial Humans Science, 296 (5570), 1085-1085 DOI: 10.1126/science.1070106
Hinde K (2009). Richer milk for sons but more milk for daughters: Sex-biased investment during lactation varies with maternal life history in rhesus macaques. American journal of human biology : the official journal of the Human Biology Council, 21 (4), 512-9 PMID: 19384860
Hrdy, S. (1990). Sex bias in nature and in history: A late 1980s reexamination of the “biological origins” argument American Journal of Physical Anthropology, 33 (S11), 25-37 DOI: 10.1002/ajpa.1330330504
Jasienska G, Nenko I, & Jasienski M (2006). Daughters increase longevity of fathers, but daughters and sons equally reduce longevity of mothers. American journal of human biology : the official journal of the Human Biology Council, 18 (3), 422-5 PMID: 16634019
Poretsky L, Seto-Young D, Shrestha A, Dhillon S, Mirjany M, Liu HC, Yih MC, & Rosenwaks Z (2001). Phosphatidyl-inositol-3 kinase-independent insulin action pathway(s) in the human ovary. The Journal of clinical endocrinology and metabolism, 86 (7), 3115-9 PMID: 11443175
Wednesday, April 20, 2011
AAPA symposium on Evolution through the Life Course: Why we shouldn't prescribe hormonal contraception to twelve year olds
When Dr. Grażyna Jasieńska invited me to give a talk on my thoughts around adolescents and hormonal contraceptives as part of an invited symposium on “Evolution through the Life Course,” I thought it was going to be an embarrassing experience, because I would not be presenting the quantitative data more common at the American Association of Physical Anthropology meetings. But I can’t say no to Grażyna, who has served as a wonderful mentor and cheerleader for almost ten years. Besides, if I can rant on a blog, surely I can let myself rant in a talk every now and then.
What follows is a bloggy version of the talk I gave Thursday the 14th, at the meetings in Minneapolis. Writing this post will, I hope, help me begin to turn this into a manuscript. Normally I wouldn’t dare write something on a blog that I would eventually want to publish. However, this is a piece that would benefit enormously from the kinds of conversations that happen in the science blogosphere. Further, I hope to publish it as an opinion piece well-studded with evidence. I think that by sharing my early thoughts now, my later thoughts will be more sophisticated.
* * *
Variation in adolescent menstrual cycles, doctor-patient relationships, and why we shouldn't prescribe hormonal contraceptives to twelve year olds
Vihko and Apter (1984) showed that there is variation in age at menarche, and that that variation tells us something about how long it should take an adolescent to start to achieve regular ovulatory cycles. The later your age at menarche, the longer you will experience irregular cycles. However, even in girls with ages at menarche twelve and under, it still took on average five years to achieve regular cycles. This indicates that, in adolescents, irregularity is in fact regular.
Lipson and Ellison (1992) have also looked at age-related variation in progesterone concentrations. Progesterone is the sex steroid hormone secreted by the ovary after ovulation, which is in the luteal phase. Luteal phase function is the one that seems to be the most variable within and between populations, and so progesterone is a great way to understand how female bodies vary. They found that those with the lowest hormone concentrations were on the extreme ends of their sample – 18-19 year olds, and 40-44 year olds and, as you might expect, hormone concentrations were higher as you moved towards the middle of that age range. So both younger and older women have low hormone concentrations relative to women in their reproductive prime, which is 25-35 years of age. But of course, this means that low hormone concentrations when you are in those early or late age ranges means that you are normal for your age.
Now, the United States has the highest rate of unintended teen pregnancy among industrialized nations. So I can understand why there are so many papers, and such a great effort, to get young girls on hormonal contraception (Clark et al. 2004; Clark 2001; Gerschultz et al. 2007; Gupta et al. 2008; Krishnamoorthy et al. 2008; Ott et al. 2002; Roye 1998; Roye and Seals 2001; Sayegh et al. 2006; Zibners et al. 1999).
But I’ve noticed two things: first, that hormonal contraception is used imperfectly in this population, with some estimates that 10-15% of adolescents on hormonal contraception still get pregnant (Gupta et al. 2008). Second, discontinuation rates for hormonal contraception in young girls are high, with many girls complaining about side effects, particularly breakthrough bleeding (Clark et al. 2004; Gupta et al. 2008; Zibners et al. 1999). I have to admit some concern over the fact that many of the papers I read that mentioned these discontinuation rates and side effects were almost condescending in their tone. The implication was that the side effects weren’t a big deal.
One of the ways clinicians and sexual health educators are trying to improve hormonal contraceptive use in adolescents is to emphasize their off-label use as a “regulator” – that is, the pill can regulate your cycle, regulate your mood, regulate your skin. The idea is to emphasize the positive effects of hormonal contraception to combat the side effects young girls both worry about, and actually experience. This also tends to produce campaigns and commercials with images of idealized young women that young girls would want to model themselves after – skinny, confident, and of course very feminine.
Despite the criticisms I’ve begun to name, there are substantial benefits to hormonal contraception in adult women. When women take hormonal contraception in adulthood, particularly in the 25-35 year range, they are very effective contraception. The pill also may reduce risk of reproductive cancers, though results are mixed (Collaborative Group 1996; Collaborative Group 2008; Kahlenborn et al. 2006; Marchbanks et al. 2002; Modan et al. 2001; Narod et al. 1998; Smith et al. 2003). And of course, off-label use to treat painful periods or premenstrual syndrome can be beneficial for many (Fraser and Kovacs 2003).
However, the benefits of hormonal contraception in adults seems to be limited to more industrialized populations. Bentley (1994; 1996) first raised these concerns. She discussed the possible genetic, ethnic and developmental differences between women that could produce variation in pharmacokinetics, which could in turn vastly change the experience and efficacy of hormonal contraception in a global context. Virginia Vitzthum and others have also shown that there are high discontinuation rates and complaints of breakthrough bleeding in rural Bolivian women on hormonal contraception (Vitzthum and Ringheim 2005; Vitzthum et al. 2001). Other studies have shown similar discontinuation rates and side effects in other non-industrial populations (de Oliveira D'Antona et al. 2009; Gubhaju 2009).
You might notice that the issues in non-industrial populations mirror what has been seen in industrial adolescent girls. This isn’t surprising, given that they also have in common fewer ovulatory cycles and lower hormone concentrations.
So, I worry about whether the clear benefits of hormonal contraception in adulthood can be applied to adolescent girls, some as young as eleven or twelve years old. With the imperfect administration and high discontinuation rates, they aren’t that great as contraception. But there are additional, physiological concerns. What are the effects of giving doses of hormones to young girls with newly developing hypothalamic-pituitary-ovarian axes? The variation I mentioned before, where irregularity is regular in adolescence, is because the feedback loop between the brain and the gonads is priming and developing in this period, and this takes time. The sensitivity of the feedback loop is being set. If we flood this feedback loop with extra hormone, does this alter its sensitivity? It is a question worth testing.
Further, if we flood this immature system that normally has irregular cycles and low hormones, are we increasing lifetime estrogen exposure? High lifetime estrogen exposure is a risk factor for breast cancer and other reproductive cancers. Is it possible that hormonal contraception in adolescence could have the opposite effect of hormonal contraception in adulthood? Again, we need to test this hypothesis.
Future work on this topic includes asking whether adolescent menstrual cycle variation is any different today than twenty to thirty years ago. The only data we have (at least that I know of) are from the aforementioned 1984 and 1992 papers, and maybe some derivative papers using the same datasets. But we all know there have been massive changes in body composition, diet and health in the last few decades that deserve consideration. So, this work needs to be re-done on a current population.
We also need to ask how adolescent reproductive functioning varies within and between populations. While this has been studied extensively in adult women, we don’t have a sense of adolescent population variation. This will give us a sense of what ecological variables produce variation not only in age at menarche, but in how long cycle irregularity persists and reproductive hormone concentrations.
Some additional, provocative, post-meeting thoughts
In this symposium, Karen Kramer delivered a beautiful paper just before mine on teen pregnancy, and I had some great conversation with session participants and attendees, that has further evolved my own thinking on this issue. I want to say something just a little provocative:
While I think teen pregnancy should be avoided, culturally we overstate its dangers and consequences because we have a real problem with young people reproducing. This can lead young girls to overlook potentially more serious issues like sexually transmitted infections, HIV, and cervical cancer, all of which girls and women are at risk for if they use only hormonal contraception and have otherwise unprotected sex.
Let me explain two important points here. First, in most industrialized nations we are not set up well to support young mothers because of the way families are isolated, yet social support is a strong predictor of birth weight, postpartum depression, and labor progression (Collins et al. 1993; Feldman et al. 2000; Turner et al. 1990). So there are very strong and obvious reasons why teen pregnancy and motherhood can be incredibly challenging in industrialized environments. I wonder sometimes if that lack of cultural support is related to a fear that more young girls will get pregnant if they feel they have permission to procreate. This is similar to the argument in favor of abstinence-only sex ed: if they don’t know their options, or are shamed into believing this option is the worst possible one, then of course they won’t make them. But adults aren’t rational. I’m unsure why we expect adolescents to be.
We also need to consider population variation in adolescence and pregnancy. Variation in age at first birth in traditional populations is quite wide, from sixteen to almost twenty six years of age (Walker et al. 2006). In more traditional populations you see a lot of allomothering and grandmothering to support first time mothers, who are often teenagers (Hawkes 2003; Hrdy 2009; Kramer 2005; Kramer 2008). So, support systems are built in, and it does not alter the trajectory of your life in the same way teen pregnancy does in an industrialized population.
This range of variation in age at first birth, and the fact that most of those young mothers do just fine, perhaps even end up with higher reproductive success, leads me to my second point: the physiological evidence against teen pregnancy might be overstated. In her talk, Karen discussed a paper of hers in the American Journal of Physical Anthropology that described the negative health outcomes of teen pregnancy (Kramer 2008). In it, she reviewed literature that suggests that when you control for lack of prenatal care, first pregnancy, and low socioeconomic status, the common assumption that pregnancy is harmful to teens is significantly weakened.
Further, in her own work with Pumé foragers in Venezuela, mothers under the age of fourteen were the only group to have greater infant mortality than the referent group of late reproducers (Kramer 2008). Yet when we teach young girls about their bodies, we tell them that their bodies are not equipped to have babies in their teens and that there are extreme consequences (in fact, I have said exactly this in the past). The reality is that those consequences are worst for very young teens, and may not be as significant in older teens.
Am I advocating teenagers get pregnant? Absolutely and unequivocally no. But I think they need access to correct information, not skewed information. This means telling them the truth about our uncertainties about the health implications for hormonal contraception in adolescence, it means educating them about the importance of barrier methods, and it means making sure they understand the health risks associated with unprotected sex.
This is a nuanced issue that requires nuanced thinking. Despite my concerns about adolescent hormone contraceptive use, there are problems with barrier methods as well, particularly when there may be a cultural bias against their use, or in situations when women cannot safely use contraception in an obvious way with their partner (Gupta et al. 2008). Again, what is important here is conveying correct information, so that each individual can weigh the pros and cons as they relate to her own context. This means it could be an excellent idea for some twelve year olds to be on hormonal contraception, and a terrible one for other girls through the age of twenty. It is going to have to be up to them.
I hope this post generates some thinking and some conversation, and I welcome people who might push me in a different direction than where I’m currently thinking. I am sharing this now, before putting it together as a manuscript, to provoke thoughts and comments.
References
Bentley GR (1994). Ranging hormones: do hormonal contraceptives ignore human biological variation and evolution? Annals of the New York Academy of Sciences, 709, 201-3 PMID: 8154705
Bentley GR. 1996. Evidence for interpopulation variation in normal ovarian function and consequences for hormonal contraception. In: Rosetta LaM-T, C.G.N., editor. Variability in human fertility. Cambridge, UK: Cambridge University Press. p 46-65.
Clark, L. (2004). Menstrual irregularity from hormonal contraception triggers significant reproductive health fears in adolescent girls Journal of Adolescent Health, 34 (2), 123-124 DOI: 10.1016/j.jadohealth.2003.11.091
Clark, L. (2001). Will the Pill Make Me Sterile? Addressing Reproductive Health Concerns and Strategies to Improve Adherence to Hormonal Contraceptive Regimens in Adolescent Girls Journal of Pediatric and Adolescent Gynecology, 14 (4), 153-162 DOI: 10.1016/S1083-3188(01)00123-1
Collaborative group (1996). Breast cancer and hormonal contraceptives: collaborative reanalysis of individual data on 53 297 women with breast cancer and 100 239 women without breast cancer from 54 epidemiological studies The Lancet, 347 (9017), 1713-1727 DOI: 10.1016/S0140-6736(96)90806-5
Collaborative Group on Epidemiological Studies of Ovarian Cancer, Beral V, Doll R, Hermon C, Peto R, & Reeves G (2008). Ovarian cancer and oral contraceptives: collaborative reanalysis of data from 45 epidemiological studies including 23,257 women with ovarian cancer and 87,303 controls. Lancet, 371 (9609), 303-14 PMID: 18294997
Collins, N., Dunkel-Schetter, C., Lobel, M., & Scrimshaw, S. (1993). Social support in pregnancy: Psychosocial correlates of birth outcomes and postpartum depression. Journal of Personality and Social Psychology, 65 (6), 1243-1258 DOI: 10.1037//0022-3514.65.6.1243
D'Antona Ade O, Chelekis JA, D'Antona MF, & Siqueira AD (2009). Contraceptive discontinuation and non-use in Santarém, Brazilian Amazon. Cadernos de saude publica / Ministerio da Saude, Fundacao Oswaldo Cruz, Escola Nacional de Saude Publica, 25 (9), 2021-32 PMID: 19750389
Feldman PJ, Dunkel-Schetter C, Sandman CA, & Wadhwa PD (2000). Maternal social support predicts birth weight and fetal growth in human pregnancy. Psychosomatic medicine, 62 (5), 715-25 PMID: 11020102
Fraser IS, & Kovacs GT (2003). The efficacy of non-contraceptive uses for hormonal contraceptives. The Medical journal of Australia, 178 (12), 621-3 PMID: 12797849
Gerschultz KL, Sucato GS, Hennon TR, Murray PJ, & Gold MA (2007). Extended cycling of combined hormonal contraceptives in adolescents: physician views and prescribing practices. The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 40 (2), 151-7 PMID: 17259055
Gubhaju, B. (2009). Barriers to Sustained Use of Contraception in Nepal: Quality of Care, Socioeconomic Status, and Method-Related Factors Biodemography and Social Biology, 55 (1), 52-70 DOI: 10.1080/19485560903054671
Gupta, N., Corrado, S., & Goldstein, M. (2008). Hormonal Contraception for the Adolescent Pediatrics in Review, 29 (11), 386-397 DOI: 10.1542/pir.29-11-386
Hawkes, K. (2003). Grandmothers and the evolution of human longevity American Journal of Human Biology, 15 (3), 380-400 DOI: 10.1002/ajhb.10156
Hrdy SB. 2009. Mothers and others: the evolutionary origins of mutual understanding: Belknap Press.
Kahlenborn, C., Modugno, F., Potter, D., & Severs, W. (2006). Oral Contraceptive Use as a Risk Factor for Premenopausal Breast Cancer: A Meta-analysis Mayo Clinic Proceedings, 81 (10), 1290-1302 DOI: 10.4065/81.10.1290
Kramer, K. (2005). Children's Help and the Pace of Reproduction: Cooperative Breeding in Humans Evolutionary Anthropology: Issues, News, and Reviews, 14 (6), 224-237 DOI: 10.1002/evan.20082
Kramer KL (2008). Early sexual maturity among Pumé foragers of Venezuela: fitness implications of teen motherhood. American journal of physical anthropology, 136 (3), 338-50 PMID: 18386795
KRISHNAMOORTHY, N., SIMPSON, C., TOWNEND, J., HELMS, P., & MCLAY, J. (2008). Adolescent Females and Hormonal Contraception: A Retrospective Study in Primary Care Journal of Adolescent Health, 42 (1), 97-101 DOI: 10.1016/j.jadohealth.2007.06.016
Lipson, S., & Ellison, P. (2008). Normative study of age variation in salivary progesterone profiles Journal of Biosocial Science, 24 (02) DOI: 10.1017/S0021932000019751
Marchbanks, P., McDonald, J., Wilson, H., Folger, S., Mandel, M., Daling, J., Bernstein, L., Malone, K., Ursin, G., Strom, B., Norman, S., Wingo, P., Burkman, R., Berlin, J., Simon, M., Spirtas, R., & Weiss, L. (2002). Oral Contraceptives and the Risk of Breast Cancer New England Journal of Medicine, 346 (26), 2025-2032 DOI: 10.1056/NEJMoa013202
Modan B, Hartge P, Hirsh-Yechezkel G, Chetrit A, Lubin F, Beller U, Ben-Baruch G, Fishman A, Menczer J, Struewing JP, Tucker MA, Wacholder S, & National Israel Ovarian Cancer Study Group (2001). Parity, oral contraceptives, and the risk of ovarian cancer among carriers and noncarriers of a BRCA1 or BRCA2 mutation. The New England journal of medicine, 345 (4), 235-40 PMID: 11474660
Narod, S., Risch, H., Moslehi, R., Dørum, A., Neuhausen, S., Olsson, H., Provencher, D., Radice, P., Evans, G., Bishop, S., Brunet, J., Ponder, B., & Klijn, J. (1998). Oral Contraceptives and the Risk of Hereditary Ovarian Cancer New England Journal of Medicine, 339 (7), 424-428 DOI: 10.1056/NEJM199808133390702
Ott, M., Adler, N., Millstein, S., Tschann, J., & Ellen, J. (2002). The Trade-Off between Hormonal Contraceptives and Condoms among Adolescents Perspectives on Sexual and Reproductive Health, 34 (1) DOI: 10.2307/3030227
ROYE, C. (1998). Condom use by hispanic and african-american adolescent girls who use hormonal contraception Journal of Adolescent Health, 23 (4), 205-211 DOI: 10.1016/S1054-139X(97)00264-4
Roye CF, & Seals B (2001). A qualitative assessment of condom use decisions by female adolescents who use hormonal contraception. The Journal of the Association of Nurses in AIDS Care : JANAC, 12 (6), 78-87 PMID: 11723916
SAYEGH, M., FORTENBERRY, J., SHEW, M., & ORR, D. (2005). The developmental association of relationship quality, hormonal contraceptive choice and condom non-use among adolescent women Journal of Adolescent Health, 36 (2), 97-97 DOI: 10.1016/j.jadohealth.2004.11.009
SMITH, J., GREEN, J., DEGONZALEZ, A., APPLEBY, P., PETO, J., PLUMMER, M., FRANCESCHI, S., & BERAL, V. (2003). Cervical cancer and use of hormonal contraceptives: a systematic review The Lancet, 361 (9364), 1159-1167 DOI: 10.1016/S0140-6736(03)12949-2
Turner, R., Grindstaff, C., & Phillips, N. (1990). Social Support and Outcome in Teenage Pregnancy Journal of Health and Social Behavior, 31 (1) DOI: 10.2307/2137044
Vihko R, & Apter D (1984). Endocrine characteristics of adolescent menstrual cycles: impact of early menarche. Journal of steroid biochemistry, 20 (1), 231-6 PMID: 6231419
Vitzthum, V., & Ringheim, K. (2005). Hormonal Contraception and Physiology: A Research-based Theory of Discontinuation Due to Side Effects Studies in Family Planning, 36 (1), 13-32 DOI: 10.1111/j.1728-4465.2005.00038.x
Vitzthum, V. (2001). Vaginal bleeding patterns among rural highland Bolivian women: relationship to fecundity and fetal loss Contraception, 64 (5), 319-325 DOI: 10.1016/S0010-7824(01)00260-8
Walker, R., Gurven, M., Hill, K., Migliano, A., Chagnon, N., De Souza, R., Djurovic, G., Hames, R., Hurtado, A., Kaplan, H., Kramer, K., Oliver, W., Valeggia, C., & Yamauchi, T. (2006). Growth rates and life histories in twenty-two small-scale societies American Journal of Human Biology, 18 (3), 295-311 DOI: 10.1002/ajhb.20510
ZIBNERS, A., CROMER, B., & HAYES, J. (1999). Comparison of continuation rates for hormonal contraception among adolescents Journal of Pediatric and Adolescent Gynecology, 12 (2), 90-94 DOI: 10.1016/S1083-3188(00)86633-4
What follows is a bloggy version of the talk I gave Thursday the 14th, at the meetings in Minneapolis. Writing this post will, I hope, help me begin to turn this into a manuscript. Normally I wouldn’t dare write something on a blog that I would eventually want to publish. However, this is a piece that would benefit enormously from the kinds of conversations that happen in the science blogosphere. Further, I hope to publish it as an opinion piece well-studded with evidence. I think that by sharing my early thoughts now, my later thoughts will be more sophisticated.
Variation in adolescent menstrual cycles, doctor-patient relationships, and why we shouldn't prescribe hormonal contraceptives to twelve year olds
 |
| From Vihko and Apter (1984). |
Lipson and Ellison (1992) have also looked at age-related variation in progesterone concentrations. Progesterone is the sex steroid hormone secreted by the ovary after ovulation, which is in the luteal phase. Luteal phase function is the one that seems to be the most variable within and between populations, and so progesterone is a great way to understand how female bodies vary. They found that those with the lowest hormone concentrations were on the extreme ends of their sample – 18-19 year olds, and 40-44 year olds and, as you might expect, hormone concentrations were higher as you moved towards the middle of that age range. So both younger and older women have low hormone concentrations relative to women in their reproductive prime, which is 25-35 years of age. But of course, this means that low hormone concentrations when you are in those early or late age ranges means that you are normal for your age.
 |
| From Lipson and Ellison (1992). |
But I’ve noticed two things: first, that hormonal contraception is used imperfectly in this population, with some estimates that 10-15% of adolescents on hormonal contraception still get pregnant (Gupta et al. 2008). Second, discontinuation rates for hormonal contraception in young girls are high, with many girls complaining about side effects, particularly breakthrough bleeding (Clark et al. 2004; Gupta et al. 2008; Zibners et al. 1999). I have to admit some concern over the fact that many of the papers I read that mentioned these discontinuation rates and side effects were almost condescending in their tone. The implication was that the side effects weren’t a big deal.
One of the ways clinicians and sexual health educators are trying to improve hormonal contraceptive use in adolescents is to emphasize their off-label use as a “regulator” – that is, the pill can regulate your cycle, regulate your mood, regulate your skin. The idea is to emphasize the positive effects of hormonal contraception to combat the side effects young girls both worry about, and actually experience. This also tends to produce campaigns and commercials with images of idealized young women that young girls would want to model themselves after – skinny, confident, and of course very feminine.
 |
| From here. |
However, the benefits of hormonal contraception in adults seems to be limited to more industrialized populations. Bentley (1994; 1996) first raised these concerns. She discussed the possible genetic, ethnic and developmental differences between women that could produce variation in pharmacokinetics, which could in turn vastly change the experience and efficacy of hormonal contraception in a global context. Virginia Vitzthum and others have also shown that there are high discontinuation rates and complaints of breakthrough bleeding in rural Bolivian women on hormonal contraception (Vitzthum and Ringheim 2005; Vitzthum et al. 2001). Other studies have shown similar discontinuation rates and side effects in other non-industrial populations (de Oliveira D'Antona et al. 2009; Gubhaju 2009).
You might notice that the issues in non-industrial populations mirror what has been seen in industrial adolescent girls. This isn’t surprising, given that they also have in common fewer ovulatory cycles and lower hormone concentrations.
So, I worry about whether the clear benefits of hormonal contraception in adulthood can be applied to adolescent girls, some as young as eleven or twelve years old. With the imperfect administration and high discontinuation rates, they aren’t that great as contraception. But there are additional, physiological concerns. What are the effects of giving doses of hormones to young girls with newly developing hypothalamic-pituitary-ovarian axes? The variation I mentioned before, where irregularity is regular in adolescence, is because the feedback loop between the brain and the gonads is priming and developing in this period, and this takes time. The sensitivity of the feedback loop is being set. If we flood this feedback loop with extra hormone, does this alter its sensitivity? It is a question worth testing.
Further, if we flood this immature system that normally has irregular cycles and low hormones, are we increasing lifetime estrogen exposure? High lifetime estrogen exposure is a risk factor for breast cancer and other reproductive cancers. Is it possible that hormonal contraception in adolescence could have the opposite effect of hormonal contraception in adulthood? Again, we need to test this hypothesis.
Future work on this topic includes asking whether adolescent menstrual cycle variation is any different today than twenty to thirty years ago. The only data we have (at least that I know of) are from the aforementioned 1984 and 1992 papers, and maybe some derivative papers using the same datasets. But we all know there have been massive changes in body composition, diet and health in the last few decades that deserve consideration. So, this work needs to be re-done on a current population.
We also need to ask how adolescent reproductive functioning varies within and between populations. While this has been studied extensively in adult women, we don’t have a sense of adolescent population variation. This will give us a sense of what ecological variables produce variation not only in age at menarche, but in how long cycle irregularity persists and reproductive hormone concentrations.
Some additional, provocative, post-meeting thoughts
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| Bristol Palin. Image from here. |
While I think teen pregnancy should be avoided, culturally we overstate its dangers and consequences because we have a real problem with young people reproducing. This can lead young girls to overlook potentially more serious issues like sexually transmitted infections, HIV, and cervical cancer, all of which girls and women are at risk for if they use only hormonal contraception and have otherwise unprotected sex.
Let me explain two important points here. First, in most industrialized nations we are not set up well to support young mothers because of the way families are isolated, yet social support is a strong predictor of birth weight, postpartum depression, and labor progression (Collins et al. 1993; Feldman et al. 2000; Turner et al. 1990). So there are very strong and obvious reasons why teen pregnancy and motherhood can be incredibly challenging in industrialized environments. I wonder sometimes if that lack of cultural support is related to a fear that more young girls will get pregnant if they feel they have permission to procreate. This is similar to the argument in favor of abstinence-only sex ed: if they don’t know their options, or are shamed into believing this option is the worst possible one, then of course they won’t make them. But adults aren’t rational. I’m unsure why we expect adolescents to be.
We also need to consider population variation in adolescence and pregnancy. Variation in age at first birth in traditional populations is quite wide, from sixteen to almost twenty six years of age (Walker et al. 2006). In more traditional populations you see a lot of allomothering and grandmothering to support first time mothers, who are often teenagers (Hawkes 2003; Hrdy 2009; Kramer 2005; Kramer 2008). So, support systems are built in, and it does not alter the trajectory of your life in the same way teen pregnancy does in an industrialized population.
This range of variation in age at first birth, and the fact that most of those young mothers do just fine, perhaps even end up with higher reproductive success, leads me to my second point: the physiological evidence against teen pregnancy might be overstated. In her talk, Karen discussed a paper of hers in the American Journal of Physical Anthropology that described the negative health outcomes of teen pregnancy (Kramer 2008). In it, she reviewed literature that suggests that when you control for lack of prenatal care, first pregnancy, and low socioeconomic status, the common assumption that pregnancy is harmful to teens is significantly weakened.
Further, in her own work with Pumé foragers in Venezuela, mothers under the age of fourteen were the only group to have greater infant mortality than the referent group of late reproducers (Kramer 2008). Yet when we teach young girls about their bodies, we tell them that their bodies are not equipped to have babies in their teens and that there are extreme consequences (in fact, I have said exactly this in the past). The reality is that those consequences are worst for very young teens, and may not be as significant in older teens.
Am I advocating teenagers get pregnant? Absolutely and unequivocally no. But I think they need access to correct information, not skewed information. This means telling them the truth about our uncertainties about the health implications for hormonal contraception in adolescence, it means educating them about the importance of barrier methods, and it means making sure they understand the health risks associated with unprotected sex.
This is a nuanced issue that requires nuanced thinking. Despite my concerns about adolescent hormone contraceptive use, there are problems with barrier methods as well, particularly when there may be a cultural bias against their use, or in situations when women cannot safely use contraception in an obvious way with their partner (Gupta et al. 2008). Again, what is important here is conveying correct information, so that each individual can weigh the pros and cons as they relate to her own context. This means it could be an excellent idea for some twelve year olds to be on hormonal contraception, and a terrible one for other girls through the age of twenty. It is going to have to be up to them.
I hope this post generates some thinking and some conversation, and I welcome people who might push me in a different direction than where I’m currently thinking. I am sharing this now, before putting it together as a manuscript, to provoke thoughts and comments.
References
Bentley GR (1994). Ranging hormones: do hormonal contraceptives ignore human biological variation and evolution? Annals of the New York Academy of Sciences, 709, 201-3 PMID: 8154705
Bentley GR. 1996. Evidence for interpopulation variation in normal ovarian function and consequences for hormonal contraception. In: Rosetta LaM-T, C.G.N., editor. Variability in human fertility. Cambridge, UK: Cambridge University Press. p 46-65.
Clark, L. (2004). Menstrual irregularity from hormonal contraception triggers significant reproductive health fears in adolescent girls Journal of Adolescent Health, 34 (2), 123-124 DOI: 10.1016/j.jadohealth.2003.11.091
Clark, L. (2001). Will the Pill Make Me Sterile? Addressing Reproductive Health Concerns and Strategies to Improve Adherence to Hormonal Contraceptive Regimens in Adolescent Girls Journal of Pediatric and Adolescent Gynecology, 14 (4), 153-162 DOI: 10.1016/S1083-3188(01)00123-1
Collaborative group (1996). Breast cancer and hormonal contraceptives: collaborative reanalysis of individual data on 53 297 women with breast cancer and 100 239 women without breast cancer from 54 epidemiological studies The Lancet, 347 (9017), 1713-1727 DOI: 10.1016/S0140-6736(96)90806-5
Collaborative Group on Epidemiological Studies of Ovarian Cancer, Beral V, Doll R, Hermon C, Peto R, & Reeves G (2008). Ovarian cancer and oral contraceptives: collaborative reanalysis of data from 45 epidemiological studies including 23,257 women with ovarian cancer and 87,303 controls. Lancet, 371 (9609), 303-14 PMID: 18294997
Collins, N., Dunkel-Schetter, C., Lobel, M., & Scrimshaw, S. (1993). Social support in pregnancy: Psychosocial correlates of birth outcomes and postpartum depression. Journal of Personality and Social Psychology, 65 (6), 1243-1258 DOI: 10.1037//0022-3514.65.6.1243
D'Antona Ade O, Chelekis JA, D'Antona MF, & Siqueira AD (2009). Contraceptive discontinuation and non-use in Santarém, Brazilian Amazon. Cadernos de saude publica / Ministerio da Saude, Fundacao Oswaldo Cruz, Escola Nacional de Saude Publica, 25 (9), 2021-32 PMID: 19750389
Feldman PJ, Dunkel-Schetter C, Sandman CA, & Wadhwa PD (2000). Maternal social support predicts birth weight and fetal growth in human pregnancy. Psychosomatic medicine, 62 (5), 715-25 PMID: 11020102
Fraser IS, & Kovacs GT (2003). The efficacy of non-contraceptive uses for hormonal contraceptives. The Medical journal of Australia, 178 (12), 621-3 PMID: 12797849
Gerschultz KL, Sucato GS, Hennon TR, Murray PJ, & Gold MA (2007). Extended cycling of combined hormonal contraceptives in adolescents: physician views and prescribing practices. The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 40 (2), 151-7 PMID: 17259055
Gubhaju, B. (2009). Barriers to Sustained Use of Contraception in Nepal: Quality of Care, Socioeconomic Status, and Method-Related Factors Biodemography and Social Biology, 55 (1), 52-70 DOI: 10.1080/19485560903054671
Gupta, N., Corrado, S., & Goldstein, M. (2008). Hormonal Contraception for the Adolescent Pediatrics in Review, 29 (11), 386-397 DOI: 10.1542/pir.29-11-386
Hawkes, K. (2003). Grandmothers and the evolution of human longevity American Journal of Human Biology, 15 (3), 380-400 DOI: 10.1002/ajhb.10156
Hrdy SB. 2009. Mothers and others: the evolutionary origins of mutual understanding: Belknap Press.
Kahlenborn, C., Modugno, F., Potter, D., & Severs, W. (2006). Oral Contraceptive Use as a Risk Factor for Premenopausal Breast Cancer: A Meta-analysis Mayo Clinic Proceedings, 81 (10), 1290-1302 DOI: 10.4065/81.10.1290
Kramer, K. (2005). Children's Help and the Pace of Reproduction: Cooperative Breeding in Humans Evolutionary Anthropology: Issues, News, and Reviews, 14 (6), 224-237 DOI: 10.1002/evan.20082
Kramer KL (2008). Early sexual maturity among Pumé foragers of Venezuela: fitness implications of teen motherhood. American journal of physical anthropology, 136 (3), 338-50 PMID: 18386795
KRISHNAMOORTHY, N., SIMPSON, C., TOWNEND, J., HELMS, P., & MCLAY, J. (2008). Adolescent Females and Hormonal Contraception: A Retrospective Study in Primary Care Journal of Adolescent Health, 42 (1), 97-101 DOI: 10.1016/j.jadohealth.2007.06.016
Lipson, S., & Ellison, P. (2008). Normative study of age variation in salivary progesterone profiles Journal of Biosocial Science, 24 (02) DOI: 10.1017/S0021932000019751
Marchbanks, P., McDonald, J., Wilson, H., Folger, S., Mandel, M., Daling, J., Bernstein, L., Malone, K., Ursin, G., Strom, B., Norman, S., Wingo, P., Burkman, R., Berlin, J., Simon, M., Spirtas, R., & Weiss, L. (2002). Oral Contraceptives and the Risk of Breast Cancer New England Journal of Medicine, 346 (26), 2025-2032 DOI: 10.1056/NEJMoa013202
Modan B, Hartge P, Hirsh-Yechezkel G, Chetrit A, Lubin F, Beller U, Ben-Baruch G, Fishman A, Menczer J, Struewing JP, Tucker MA, Wacholder S, & National Israel Ovarian Cancer Study Group (2001). Parity, oral contraceptives, and the risk of ovarian cancer among carriers and noncarriers of a BRCA1 or BRCA2 mutation. The New England journal of medicine, 345 (4), 235-40 PMID: 11474660
Narod, S., Risch, H., Moslehi, R., Dørum, A., Neuhausen, S., Olsson, H., Provencher, D., Radice, P., Evans, G., Bishop, S., Brunet, J., Ponder, B., & Klijn, J. (1998). Oral Contraceptives and the Risk of Hereditary Ovarian Cancer New England Journal of Medicine, 339 (7), 424-428 DOI: 10.1056/NEJM199808133390702
Ott, M., Adler, N., Millstein, S., Tschann, J., & Ellen, J. (2002). The Trade-Off between Hormonal Contraceptives and Condoms among Adolescents Perspectives on Sexual and Reproductive Health, 34 (1) DOI: 10.2307/3030227
ROYE, C. (1998). Condom use by hispanic and african-american adolescent girls who use hormonal contraception Journal of Adolescent Health, 23 (4), 205-211 DOI: 10.1016/S1054-139X(97)00264-4
Roye CF, & Seals B (2001). A qualitative assessment of condom use decisions by female adolescents who use hormonal contraception. The Journal of the Association of Nurses in AIDS Care : JANAC, 12 (6), 78-87 PMID: 11723916
SAYEGH, M., FORTENBERRY, J., SHEW, M., & ORR, D. (2005). The developmental association of relationship quality, hormonal contraceptive choice and condom non-use among adolescent women Journal of Adolescent Health, 36 (2), 97-97 DOI: 10.1016/j.jadohealth.2004.11.009
SMITH, J., GREEN, J., DEGONZALEZ, A., APPLEBY, P., PETO, J., PLUMMER, M., FRANCESCHI, S., & BERAL, V. (2003). Cervical cancer and use of hormonal contraceptives: a systematic review The Lancet, 361 (9364), 1159-1167 DOI: 10.1016/S0140-6736(03)12949-2
Turner, R., Grindstaff, C., & Phillips, N. (1990). Social Support and Outcome in Teenage Pregnancy Journal of Health and Social Behavior, 31 (1) DOI: 10.2307/2137044
Vihko R, & Apter D (1984). Endocrine characteristics of adolescent menstrual cycles: impact of early menarche. Journal of steroid biochemistry, 20 (1), 231-6 PMID: 6231419
Vitzthum, V., & Ringheim, K. (2005). Hormonal Contraception and Physiology: A Research-based Theory of Discontinuation Due to Side Effects Studies in Family Planning, 36 (1), 13-32 DOI: 10.1111/j.1728-4465.2005.00038.x
Vitzthum, V. (2001). Vaginal bleeding patterns among rural highland Bolivian women: relationship to fecundity and fetal loss Contraception, 64 (5), 319-325 DOI: 10.1016/S0010-7824(01)00260-8
Walker, R., Gurven, M., Hill, K., Migliano, A., Chagnon, N., De Souza, R., Djurovic, G., Hames, R., Hurtado, A., Kaplan, H., Kramer, K., Oliver, W., Valeggia, C., & Yamauchi, T. (2006). Growth rates and life histories in twenty-two small-scale societies American Journal of Human Biology, 18 (3), 295-311 DOI: 10.1002/ajhb.20510
ZIBNERS, A., CROMER, B., & HAYES, J. (1999). Comparison of continuation rates for hormonal contraception among adolescents Journal of Pediatric and Adolescent Gynecology, 12 (2), 90-94 DOI: 10.1016/S1083-3188(00)86633-4
Tuesday, April 12, 2011
Come hang out with the cool kids: the 2011 American Association of Physical Anthropology Meetings, Minneapolis
Biological anthropologists are a cool lot. We study bones, death, fossils, phylogenetics (how things are related to each other), hominin evolution, behavior, reproduction, physiology, primates, communication, cognition, genetics, migration and more. We study how these things vary, what produces their variation, and why that variation is meaningful. So the AAPAs tend to be a fun conference full of lively conversation, strong sessions, and engaged attendees.
Plus, you see a lot of people wearing sandals with socks.
This year, that particular population might be slightly underrepresented, because we are having the meetings in Minneapolis, where snow is predicted on Friday and Saturday. While that has impacted the wardrobe that will be crammed into my carry-on luggage tomorrow, I still expect a great meeting, because there are several wonderful symposia planned, a lunch event for women in biological anthropology, and a BANDIT Happy Hour on Saturday at 5pm. Julienne Rutherford has curated a great list that can be found by reading the posts under her AAPA label.
Me? I'm going to self-promote, but I'll encourage you to do the same in the comments.
On Thursday morning you can find me in Session 3, the invited podium symposium chaired by Grazyna Jasienska and Diana Sherry entitled "Evolution and Health over the Life Course" in Salon C. The session starts at 8am with what looks to be a great talk by Beverly Strassmann, "Evolution and health from infancy to adolescence in the Dogon of Mali."
My talk is at 9:30am, is co-authored with my former students Theresa Emmerling and Ashley Higgins, and is entitled "Variation in adolescent menstrual cycles, doctor-patient relationships, and why we shouldn't prescribe hormonal contraceptives to twelve year olds." I'll be talking about what we know of adolescent menstrual cycle variation, what we know of the impact of hormonal contraception on different reproductively-aged women, and some pilot data from our focus groups on doctor-patient relationships. I hope the last bit will provide a bit of framework for understanding how and why US women use hormonal contraception in such comparatively high proportions for off-label use.
On Friday afternoon, you can find me in Session 31, the invited podium symposium chaired by Julienne Rutherford and me entitled "Eating for Two: Maternal Ecology and Nutrition in Human and Non-Human Primates" in Marquette V/VI. The session starts at 2pm with a talk by Betsey Abrams and Julienne Rutherford entitled "Risky business: an evolutionary perspective on placental nutrient transport and postpartum hemorrage." I am VERY excited to hear this paper!
My talk is next, at 2:15pm, and is called "Pro- and anti-inflammatory food proteins and their impact on maternal ecology." This talk is co-authored by two of my students, Laura Klein and Katherine Tribble. I'll be doing a bit of a review of the literature to place this topic in context, and discussing some pilot data.
I may be biased, but the rest of this symposium is pretty kick-ass.
Science bloggers and writers, like any of the topics above? Consider interviewing some of these symposium participants! You won't be disappointed.
Plus, you see a lot of people wearing sandals with socks.
This year, that particular population might be slightly underrepresented, because we are having the meetings in Minneapolis, where snow is predicted on Friday and Saturday. While that has impacted the wardrobe that will be crammed into my carry-on luggage tomorrow, I still expect a great meeting, because there are several wonderful symposia planned, a lunch event for women in biological anthropology, and a BANDIT Happy Hour on Saturday at 5pm. Julienne Rutherford has curated a great list that can be found by reading the posts under her AAPA label.
Me? I'm going to self-promote, but I'll encourage you to do the same in the comments.
On Thursday morning you can find me in Session 3, the invited podium symposium chaired by Grazyna Jasienska and Diana Sherry entitled "Evolution and Health over the Life Course" in Salon C. The session starts at 8am with what looks to be a great talk by Beverly Strassmann, "Evolution and health from infancy to adolescence in the Dogon of Mali."
My talk is at 9:30am, is co-authored with my former students Theresa Emmerling and Ashley Higgins, and is entitled "Variation in adolescent menstrual cycles, doctor-patient relationships, and why we shouldn't prescribe hormonal contraceptives to twelve year olds." I'll be talking about what we know of adolescent menstrual cycle variation, what we know of the impact of hormonal contraception on different reproductively-aged women, and some pilot data from our focus groups on doctor-patient relationships. I hope the last bit will provide a bit of framework for understanding how and why US women use hormonal contraception in such comparatively high proportions for off-label use.
On Friday afternoon, you can find me in Session 31, the invited podium symposium chaired by Julienne Rutherford and me entitled "Eating for Two: Maternal Ecology and Nutrition in Human and Non-Human Primates" in Marquette V/VI. The session starts at 2pm with a talk by Betsey Abrams and Julienne Rutherford entitled "Risky business: an evolutionary perspective on placental nutrient transport and postpartum hemorrage." I am VERY excited to hear this paper!
My talk is next, at 2:15pm, and is called "Pro- and anti-inflammatory food proteins and their impact on maternal ecology." This talk is co-authored by two of my students, Laura Klein and Katherine Tribble. I'll be doing a bit of a review of the literature to place this topic in context, and discussing some pilot data.
I may be biased, but the rest of this symposium is pretty kick-ass.
- 2:30 Yildirim et al speak on vaginal microbial communities and maternal ecology (University of Illinois research!)
- 2:45 Milich et al discuss habitat quality and reproduction in female red colobus monkeys (University of Illinois research!)
- 3:00 Julienne Rutherford has prepared a version of her talk to be shown at 3pm on energetics and life history plasticity in callitrichine primates as she is on maternal hiatus
- 3:15 Valeggia shares insights into the metaboliv regulation of postpartum fecundity
- 3:30 Nyberg discusses HPA activity in pregnant and lactating Tsimane' women
- 3:45 Miller shares recent work on breastmilk immunity in Ariaal women
- 4:00 Pablo Nepomnaschy will be the discussant for the first half of our symposium.
- 4:15 In our second half, Hinde et al discuss commensal gut bacteria and breastmilk
- 4:30 Quinn and Kuzawa developmental trajectories in infants and later milk composition
- 4:45 Fairbanks shares her work on nutrition, energetics and vervet maternal investment
- 5:00 Piperata and Guatelli-Steinberg discuss how social support may impact the costs of reproduction
- 5:15 Dunsworth et al look at some very interesting data on energetics versus pelvic constraint in determining human gestational length
- 5:30 Finally, Leslie Aiello wraps it up as the discussant of the second half of our symposium.
Science bloggers and writers, like any of the topics above? Consider interviewing some of these symposium participants! You won't be disappointed.
Thursday, March 24, 2011
Around the web: put attention where it needs to be put
Yesterday I submitted a book chapter and a journal manuscript. I have two substantial blog posts I'm working on, but neither will be ready for this week. However, I have been slowly accumulating Posts of Awesome that I'd like to share. I want to highlight people, writing, and topics that need and deserve more attention in the science blogosphere. I mention a lot of these things on Twitter, but I know a lot of my followers don't use Twitter. So here goes.
Ladybusiness
If you have any interest in pregnancy, labor and birth, I do hope you're reading Science and Sensibility. S&S is a evidence-based blog written by practitioners and scientists, sponsored by Lamaze International. I really like their more technical, informative posts on labor and birth, and today's post on positioning during the second stage of labor is a winner. The writing is always accessible for layfolks, yet still provides great information for scientists and medical folk.
Remember that Wax et al (2010) article showing homebirth had a mortality rate three times higher than a hospital birth (and the sensational Lancet editorial)? A lot of folks came down hard on the article when it first came out, myself included, but two more pieces came out yesterday that call into question the authors' conclusions. The first issue is that there were actual mathematical errors in the data (meaning, the data was probably entered into an excel sheet incorrectly), the second is that they fundamentally did the meta-analysis wrong. Wrong. As in, according to one statistician who had no stake in the story or topic, so wrong as to overlook all its other problems.
A few more spicy tidbits: cosmetic breast surgery is on the rise, and one county in Florida has a 70% cesarean rate. Seventy. Percent. Due to some smart marketing and bad decisions, a treatment to prevent pre-term birth that used to be affordable is now more expensive than gold.
Something a little more fun: older female elephants make better leaders. Here's a video to go with the paper.
Finally, this is sort of ladybusiness, but as Dr. Isis points out, it should really be family (or even just human) business: Why it's alright to not be your mother, a guest post on AGORA.
Queering biology
The reverberations from Jesse Bering's post on homophobia as an adaptation continue. And the responses have been brilliant. I especially love Jeremy Yoder's take over at his blog, Denim and Tweed: An adaptive fairytale with no happy ending.
And then today, DeLene Beeland shared this great post on Twitter: How to Queer Ecology: One Goose at a Time over at Orion Magazine. This is a beautifully-written, thoughtful takedown of the naturalistic fallacy.
Other things to read right now
Danielle Lee has two great pieces worth reading (and I found them both because of Greg Laden): an article on the contribution of Henrietta Lacks, and the Black community, to cell culture, and a profile on Danielle in a natural hair series at Essence.com.
I read this article today by Gina Trapani on her work to make the technical world more friendly to women and other underrepresented or new folks.
An interesting interview and review of the book Consumption
, by Kevin Patterson: How western diets are making the world sick.
A piece on Impostor Syndrome at SciAm (behind a paywall). I don't want to pathologize all underrepresented groups in science (because frankly, these feelings make sense in the context of environment, even if it's desirable to move beyond them), but issues around impostor syndrome resonate with me.
The video for the MLK, Jr session from Science Online 2011 is now up. Alberto Roca, Danielle Lee and David Kroll are the fabulous panelists.
Things I wish I didn't have to link to
Our amusement with Charlie Sheen just demonstrates how little we care about violence against women -- especially certain kinds of women. Read The Disposable Woman.
Skepchick Rebecca Watson shares some of her hate mail, and why she doesn't feel like internetting today: Why I deserved to be called an offensive bitch.
Pat Campbell reposted a twelve-year-old manifesto on gender and education that still holds true: The Gender Wars Must Cease.
Some LOLz and some cutes: a section I added because the last three links were so depressing
This first link doesn't exactly bring the LOLz, but is an enjoyable read: Female Science Professor continues her series on Academic Novels.
Some great apes from Zooborns: a two new baby orangs, and baby chimp. They put my maternal instinct into overdrive.
And a LOLcat via Scicurious: I'z in yer papers, messin' wit yer stats.
References
Wax, J., Lucas, F., Lamont, M., Pinette, M., Cartin, A., & Blackstone, J. (2010). Maternal and newborn outcomes in planned home birth vs planned hospital births: a metaanalysis American Journal of Obstetrics and Gynecology DOI: 10.1016/j.ajog.2010.05.028
Editorial staff (2010). Home birth--proceed with caution. Lancet, 376 (9738) PMID: 20674705
Ladybusiness
If you have any interest in pregnancy, labor and birth, I do hope you're reading Science and Sensibility. S&S is a evidence-based blog written by practitioners and scientists, sponsored by Lamaze International. I really like their more technical, informative posts on labor and birth, and today's post on positioning during the second stage of labor is a winner. The writing is always accessible for layfolks, yet still provides great information for scientists and medical folk.
Remember that Wax et al (2010) article showing homebirth had a mortality rate three times higher than a hospital birth (and the sensational Lancet editorial)? A lot of folks came down hard on the article when it first came out, myself included, but two more pieces came out yesterday that call into question the authors' conclusions. The first issue is that there were actual mathematical errors in the data (meaning, the data was probably entered into an excel sheet incorrectly), the second is that they fundamentally did the meta-analysis wrong. Wrong. As in, according to one statistician who had no stake in the story or topic, so wrong as to overlook all its other problems.
A few more spicy tidbits: cosmetic breast surgery is on the rise, and one county in Florida has a 70% cesarean rate. Seventy. Percent. Due to some smart marketing and bad decisions, a treatment to prevent pre-term birth that used to be affordable is now more expensive than gold.
Something a little more fun: older female elephants make better leaders. Here's a video to go with the paper.
Finally, this is sort of ladybusiness, but as Dr. Isis points out, it should really be family (or even just human) business: Why it's alright to not be your mother, a guest post on AGORA.
Queering biology
The reverberations from Jesse Bering's post on homophobia as an adaptation continue. And the responses have been brilliant. I especially love Jeremy Yoder's take over at his blog, Denim and Tweed: An adaptive fairytale with no happy ending.
And then today, DeLene Beeland shared this great post on Twitter: How to Queer Ecology: One Goose at a Time over at Orion Magazine. This is a beautifully-written, thoughtful takedown of the naturalistic fallacy.
Other things to read right now
Danielle Lee has two great pieces worth reading (and I found them both because of Greg Laden): an article on the contribution of Henrietta Lacks, and the Black community, to cell culture, and a profile on Danielle in a natural hair series at Essence.com.
I read this article today by Gina Trapani on her work to make the technical world more friendly to women and other underrepresented or new folks.
An interesting interview and review of the book Consumption
, by Kevin Patterson: How western diets are making the world sick.A piece on Impostor Syndrome at SciAm (behind a paywall). I don't want to pathologize all underrepresented groups in science (because frankly, these feelings make sense in the context of environment, even if it's desirable to move beyond them), but issues around impostor syndrome resonate with me.
The video for the MLK, Jr session from Science Online 2011 is now up. Alberto Roca, Danielle Lee and David Kroll are the fabulous panelists.
Things I wish I didn't have to link to
Our amusement with Charlie Sheen just demonstrates how little we care about violence against women -- especially certain kinds of women. Read The Disposable Woman.
Skepchick Rebecca Watson shares some of her hate mail, and why she doesn't feel like internetting today: Why I deserved to be called an offensive bitch.
Pat Campbell reposted a twelve-year-old manifesto on gender and education that still holds true: The Gender Wars Must Cease.
Some LOLz and some cutes: a section I added because the last three links were so depressing
This first link doesn't exactly bring the LOLz, but is an enjoyable read: Female Science Professor continues her series on Academic Novels.
Some great apes from Zooborns: a two new baby orangs, and baby chimp. They put my maternal instinct into overdrive.
And a LOLcat via Scicurious: I'z in yer papers, messin' wit yer stats.
References
Wax, J., Lucas, F., Lamont, M., Pinette, M., Cartin, A., & Blackstone, J. (2010). Maternal and newborn outcomes in planned home birth vs planned hospital births: a metaanalysis American Journal of Obstetrics and Gynecology DOI: 10.1016/j.ajog.2010.05.028
Editorial staff (2010). Home birth--proceed with caution. Lancet, 376 (9738) PMID: 20674705
Tuesday, March 22, 2011
The Open Laboratory 2010: for sale now!
Looking for once place to read the best science writing of 2010? Want a peer-reviewed resource that you can show your colleagues that are social media naysayers to demonstrate the power of science blogs? Look no more: Open Lab 2010 is now available for purchase at Lulu.com!
Two of my posts on IVF were selected for Open Lab (to be put into one essay). I'm brushing shoulders with some very fancy writers. I do hope you'll buy it.
Two of my posts on IVF were selected for Open Lab (to be put into one essay). I'm brushing shoulders with some very fancy writers. I do hope you'll buy it.
Thursday, March 17, 2011
Science Online 2011: Perils of blogging as a woman under a real name
If you haven't seen it yet, or just want to relive it, our women in science blogging panel is now available for viewing:
Key highlights: when I told the audience about how I squatted over a toilet to birth my baby. Oh, there was also a lot of great feminism in there too.
This is the panel that inspired this post, and then these great posts.
Perils of Blogging as a Woman under a Real Name from Smartley-Dunn on Vimeo.
Key highlights: when I told the audience about how I squatted over a toilet to birth my baby. Oh, there was also a lot of great feminism in there too.
This is the panel that inspired this post, and then these great posts.
Wednesday, March 9, 2011
Around the web: sex, birth, brainz
This semester I have decided not to do weekly roundups of links useful to the courses I teach, because last semester it was exhausting to me, and as it turns out only minimally read by my students. However, I continue to bookmark stuff I find interesting, and I have reached such a critical mass that I've decided to share it. Some of what I want to share is focused on the ladybusiness, but I also want to share some links on brainz, and for students.
Let's talk about sex
A few posts have come out recently on sex: who wants it, who gets it, and the sexual health of adolescents. Mark Regnerus writes "Sex is Cheap: Why young men have the upper hand, even when they're failing at life," which I thought was reductive and pretty disparaging to both young men and women. I was surprised at how the author talked only about heterosexual sex (why is this ok? why is this interesting?), and how he shared a single quote for each woman he interviewed, and magically it fit nicely into his own narrative. It seems like the story here is in the choices young women and men are making... so it would make sense to share the more nuanced results of the interviews Regnerus says he conducted. That said, I did learn a few things, the most disheartening related to unwanted sex:
Let's talk about sex
A few posts have come out recently on sex: who wants it, who gets it, and the sexual health of adolescents. Mark Regnerus writes "Sex is Cheap: Why young men have the upper hand, even when they're failing at life," which I thought was reductive and pretty disparaging to both young men and women. I was surprised at how the author talked only about heterosexual sex (why is this ok? why is this interesting?), and how he shared a single quote for each woman he interviewed, and magically it fit nicely into his own narrative. It seems like the story here is in the choices young women and men are making... so it would make sense to share the more nuanced results of the interviews Regnerus says he conducted. That said, I did learn a few things, the most disheartening related to unwanted sex:
"Finally, as my colleagues and I discovered in our interviews, striking numbers of young women are participating in unwanted sex—either particular acts they dislike or more frequent intercourse than they'd prefer or mimicking porn (being in a dating relationship is correlated to greater acceptance of and use of porn among women)."
Unwanted sex is one of those gray areas where the sex is technically consensual... but one partner doesn't really want to do it. How have we gotten to the point that more young women don't feel it's ok to say no to their partners? I don't think it's because of a poor dating pool as seems to be the working hypothesis of the author, but I'd be interested to hear your thoughts.
To contrast, Yes Means Yes
is an anthology edited by Jaclyn Friedman and Jessica Valenti that became a blog to continue the conversation on rape culture and female sexual empowerment. In a post on said blog, Gender Differences and Casual Sex: The New Research they look at some of the same material as the post above, as well as a new paper by Terri Conley showing that men and women aren't that different in their perspectives on casual sex as was once thought. The blog contributor, named Thomas, does a great rundown of the study's findings and explains how earlier studies of casual sex -- like the study many of you have likely heard of, where men and women are randomly propositioned in public -- is both unlikely and particularly repulsive to women given rape culture, and therefore sets up a sex difference that a more nuanced study easily demolishes.
is an anthology edited by Jaclyn Friedman and Jessica Valenti that became a blog to continue the conversation on rape culture and female sexual empowerment. In a post on said blog, Gender Differences and Casual Sex: The New Research they look at some of the same material as the post above, as well as a new paper by Terri Conley showing that men and women aren't that different in their perspectives on casual sex as was once thought. The blog contributor, named Thomas, does a great rundown of the study's findings and explains how earlier studies of casual sex -- like the study many of you have likely heard of, where men and women are randomly propositioned in public -- is both unlikely and particularly repulsive to women given rape culture, and therefore sets up a sex difference that a more nuanced study easily demolishes.Birth and babies
Randi Hutter Epstein, author of Get Me Out: A History of Childbirth from the Garden of Eden to the Sperm Bank
, wrote a short but sweet piece on labor inductions in Psychology Today. She shares some of the shortcomings of a medical model that thinks that any labor over thirty seven weeks can be safely induced. This relates to a recent story about a March of Dimes initiative to reduce early inductions, and some hospitals in the Chicago area are taking part.
, wrote a short but sweet piece on labor inductions in Psychology Today. She shares some of the shortcomings of a medical model that thinks that any labor over thirty seven weeks can be safely induced. This relates to a recent story about a March of Dimes initiative to reduce early inductions, and some hospitals in the Chicago area are taking part.And, while I wrote this a little while ago, it seems important to link the above to the kerfuffle that arose when a study came out last year claiming that home births were far more dangerous than hospital births, and the editors of the Lancet used the study as a chance to jump up and down on home birth. Given that only half of a percent of women in the US do home births, it makes more sense to use this as an opportunity not to bash home births but have a frank conversation about whether the cascade of interventions guaranteed by stepping into a hospital to give birth leads to a safer delivery for mom and baby.
Next, Scicurious of tag-team blogging fame and general awesomeness, has a real winner. Today, she reviewed cool research on sex roles from the seventies. She shows how our perception of the gender of a baby impacts how we treat it (and how dolls might make better toys than footballs for babies, no matter what).
Next, Scicurious of tag-team blogging fame and general awesomeness, has a real winner. Today, she reviewed cool research on sex roles from the seventies. She shows how our perception of the gender of a baby impacts how we treat it (and how dolls might make better toys than footballs for babies, no matter what).
And then, for your dose of cute (well, cute if you don't mind amniotic sacs and vaginas, which I don't), here are Five Miraculous Animal Births (don't know why they are miraculous, but they are certainly cool).
Brainz
First, Sci has another great post, this time on research on exercise, hippocampus size and memory in the elderly that made me vow to play derby until I need a cane to skate.
You might have seen the recent buzz about PKMZeta, a protein that may aid in strengthening old memories. Ed Yong of Not Exactly Rocket Science (check out the spiffy new banner!) has a three-part series on it. I also loved David Dobbs's piece exploring problems in cognitive science: Is Cognitive Science Full of Crap? (Yes. Well, sometimes. Maybe. Except sometimes not and then it's really very cool.) John Hawks also has an interesting piece called Numbers as Cognitive Technology: this post explores how we understand numbers, at a population variation (regarding language), developmental (regarding John's twins, who I imagine to be very cute, with thought bubbles of fingers and toes above their heads) and even comparative (Alex the Parrot!) level.
Then, a more devastating piece that, to me, highlights some of the problems with the medical metaphor of humans as machines: Daniel Lende at Neuroanthropology writes about a New York Times piece about how the field of psychiatry has changed with time.
You might have seen the recent buzz about PKMZeta, a protein that may aid in strengthening old memories. Ed Yong of Not Exactly Rocket Science (check out the spiffy new banner!) has a three-part series on it. I also loved David Dobbs's piece exploring problems in cognitive science: Is Cognitive Science Full of Crap? (Yes. Well, sometimes. Maybe. Except sometimes not and then it's really very cool.) John Hawks also has an interesting piece called Numbers as Cognitive Technology: this post explores how we understand numbers, at a population variation (regarding language), developmental (regarding John's twins, who I imagine to be very cute, with thought bubbles of fingers and toes above their heads) and even comparative (Alex the Parrot!) level.
Then, a more devastating piece that, to me, highlights some of the problems with the medical metaphor of humans as machines: Daniel Lende at Neuroanthropology writes about a New York Times piece about how the field of psychiatry has changed with time.
Oh, and this one was absolutely nothing to do with brainz, but it's written by Dr. Zen of NeuroDojo so I've shoehorned him in here :). Dr. Zen looks at the two peer-reviewed papers to come out after the #arseniclife fiasco and shows how one in particular intentionally miscategorizes the great post-peer review that happened on blogs as "anonymous electronic communications," since in fact the majority of the commenters were using their own names (and even if they weren't, again, there is a big difference between anonymous and pseudonymous). This sounds an awful lot like the response that came out after #aaafail, where, rather than addressing the many critical, thoughtful bloggers, it all got labeled as "outside commentary."
Learning links
First, for graduate students: Mamacademic: How I hack parenthood, grad school, etc. A nice piece on the perils of parenthood, because it is constructive. Then, a related post both on pregnancy style and how to deal with questions around parenting in graduate school. And while this next post isn't directly about grad students, GayProf discusses a disturbing panel he attended where faculty recommended having children in order to achieve work/life balance, a way that was clearly not situated in the context of whether one wants to have children, and who ends up doing most of the work of childrearing. Not to mention, you know, the rampant heterosexism.
But on to the links you actually expected under this heading. Dan Simons, fellow prof here at the University of Illinois and co-author of The Invisible Gorilla
, wrote a great piece on study habits and what students think they know versus what they actually know. Read it, then study the way he tells you to! Hint: re-reading the text is not how you learn the material.
Then there is this perspective over at Observations, a Scientific American blog, that posits we should teach kids more about the process of science. How can this translate into better science ed in higher ed as well? I'd love to hear your thoughts. Most of what I do centers on having students do actual studies, or assist in research in my lab, or sometimes propose avenues of research as part of a project. But maybe there are more fun things we can be doing in a classroom setting that would lead to more students understanding the scientific method and the process of science.
I also want to share this great tutorial on how to choose a research project. This is useful for students at all levels... and post-docs and faculty, too.
Your dose of random
Steve Silberman interviews Seth Mnookin regarding his new book The Panic Virus
. I've been avidly reading all of Mnookin's press materials and look forward to reading the book, but as always Silberman does an exceptional job so I particularly recommend his post.
This article made the rounds in the twittersphere on how to improve comment sections. I just liked it a lot and found it a great tutorial on fostering online communities.
Then, for my anthropology peeps, an important article on problematizing the thrifty gene, particularly around race and racism. Something to share with your students.
People have been rocking out in the SciAm Guest Blog. Check out this book review of Tabloid Medicine: How the Internet is Being Used to Hijack Medical Science for Fear and Profit
by Valerie Jones.
If you haven't had enough counter-evidence to the idea of science blogs as an echo chamber, check out Colin Schultz's treatment of a recent paper on linking patterns in science blogs versus traditional journalism.
Finally, check out this interactive map on well-being in the US in the New York Times. I found a lot of the patterns really interesting, in terms of what portions of the US lit up when.
[11:26am CST: Edited to add two links for Scicurious, because the links were on my list but then I forgot.]
But on to the links you actually expected under this heading. Dan Simons, fellow prof here at the University of Illinois and co-author of The Invisible Gorilla
, wrote a great piece on study habits and what students think they know versus what they actually know. Read it, then study the way he tells you to! Hint: re-reading the text is not how you learn the material.Then there is this perspective over at Observations, a Scientific American blog, that posits we should teach kids more about the process of science. How can this translate into better science ed in higher ed as well? I'd love to hear your thoughts. Most of what I do centers on having students do actual studies, or assist in research in my lab, or sometimes propose avenues of research as part of a project. But maybe there are more fun things we can be doing in a classroom setting that would lead to more students understanding the scientific method and the process of science.
I also want to share this great tutorial on how to choose a research project. This is useful for students at all levels... and post-docs and faculty, too.
Your dose of random
Steve Silberman interviews Seth Mnookin regarding his new book The Panic Virus
. I've been avidly reading all of Mnookin's press materials and look forward to reading the book, but as always Silberman does an exceptional job so I particularly recommend his post.This article made the rounds in the twittersphere on how to improve comment sections. I just liked it a lot and found it a great tutorial on fostering online communities.
Then, for my anthropology peeps, an important article on problematizing the thrifty gene, particularly around race and racism. Something to share with your students.
People have been rocking out in the SciAm Guest Blog. Check out this book review of Tabloid Medicine: How the Internet is Being Used to Hijack Medical Science for Fear and Profit
by Valerie Jones.If you haven't had enough counter-evidence to the idea of science blogs as an echo chamber, check out Colin Schultz's treatment of a recent paper on linking patterns in science blogs versus traditional journalism.
Finally, check out this interactive map on well-being in the US in the New York Times. I found a lot of the patterns really interesting, in terms of what portions of the US lit up when.
[11:26am CST: Edited to add two links for Scicurious, because the links were on my list but then I forgot.]
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