Monday, June 27th 2022

Passive metaphors of pregnancy, and what it means for abortion

I was on Facebook after the Supreme Court’s Roe decision. Bad idea, right? Yet it was more heartening than I expected; friends and acquaintances with whom I’d never discussed abortion were posting memes and thoughts about how enraged they were. There was shared grief, problem solving, organizing.

Then of course there were the comments.

Anti-abortion commenters were crowing below these posts about how great it was that now more deaths would be prevented… as though abortion does not save lives. The more I read, the more the wording got to me. One commenter on a high school friend’s post insisted that the fetus is “a separate person connected to your body. You can choose for your body but not for a separate little person.”

That’s the comment that pushed me over the edge.

I know anti-abortion people do not care about the truth of how abortion is necessary healthcare; this is not an information deficit issue but a power one. I want to point out though that the way we often teach and talk about pregnancy is part of what allows anti-abortion people to imagine this separateness between the parent and fetus, and to dehumanize and limit the rights of pregnant people.

As an example, in Dr. Rene Almeling’s book GUYnecology, she interviews a range of men about their understanding of pregnancy. Many of them began their descriptions with what is still a common framing: that the sperm is active, the egg passive (not accurate but that’s for another time). About half of the sample eventually arrived at an egalitarian description after some initial fumbling, but half were still staunch believers that the uterus is a “baby basket” or that “you come from your father.”

Many others have written of this problematic framing (most famously, perhaps, Dr. Emily Martin’s article “The Sperm and the Egg” and her book The Woman in the Body). There is also a longer conversation to be had here about the extent to which this framing comes from the expectations of normative white femininity and is therefore rooted in white supremacy (if ever there was a plug for my upcoming book, it’s this!). But today I want to explain the consequences.

When you see a uterus as, at best, a parking space for a car, it’s not just that you miss out on all the glorious, interconnected things that the uterus does in conversation with the parent’s brain, heart, lungs, ovaries, their stress hormones and other chemical signals… though you do. Trophoblasts, placentas, and eventually fetuses need biofeedback from the parent to receive information from the parent about the world outside – from the way the parent’s heart slows or races, how their breathing changes, what hormones they excrete. The reason extremely premature babies have a high death rate and tend to have a number of health issues is not that our external incubators in NICUs are not good. It’s that incubation only achieves the barest minimum of what a living, breathing, thinking, pregnant person does for a fetus. “Separation” is a myth.

The consequence beyond how we gloss over the science is that without understanding that interconnection you miss how much it means to be pregnant – by thinking of a uterus as a parking space you miss the costs of pregnancy. You miss the way autonomy is built into the system and how that system protects the parent over the fetus. You dehumanize the incubator.

Scientists used to think that undernourished pregnant people would put all available resource into the growth of their fetus, so any scrap of extra food went straight to the fetus – Professor Meredith Reiches at UMass-Boston calls this the “infant priority model.” We now know the pregnant person’s body does the opposite, and rather than beefing up a fetus extra calories go to that parent. The extra calories might become additional energy available for activity, they might become fat reserves, and in fact in natural fertility samples (people who do not use medical or barrier contraception) this extra energy does not make babies bigger but shortens the interval between births. It improves that parent’s chances for further reproductive success with more babies, rather than shunting more energy into a bigger baby so that individual baby has a stronger start.

The pregnant body does incredible things to provide resources and information to its fetus. And it also creates firm boundaries to ensure the fetus doesn’t overdo it and take more than it can give (which by the way, if you’ve been pregnant, you know is still a freaking lot). The idea of a baby basket, a parking space, an incubator, whatever passive metaphor you want to use breaks down when you know how pregnancy works. And it lays bare the terror of having to do all this work to care for a fetus when someone does not want to, and/or when something has gone wrong in the process (e.g., ectopic pregnancy, infection).

Again, I know anti-abortion people do not care about the truth. I also know a scientific justification for abortion is not necessary to support abortion – simple respect for every person’s bodily autonomy should actually be enough. But if we could change the metaphors – if we could talk differently about how pregnancy works and what it does and the role of the whole pregnant person – we at least wouldn’t be doing some of the work for them.


Almeling, R. (2020). Chapter 5: Sex, Sperm, and Fatherhood. GUYnecology: The Missing Science of Men’s Reproductive Health, University of California Press.

Martin, E. (1980). The Woman in the Body: A Cultural Analysis of Reproduction. Boston, Beacon Press.

Martin, E. (1991). “The egg and the sperm: how science has constructed a romance based on stereotypical male-female roles.” Signs 16(3): 485-501.

Reiches, M. (2019). “Reproductive Justice and the History of Prenatal Supplementation: Ethics, Birth Spacing, and the “Priority Infant” Model in The Gambia: Winner of the 2019 Catharine Stimpson Prize for Outstanding Feminist Scholarship.” Signs 45(1): 3-26.

Monday, June 6th 2011

Around the web: belated mother’s day edition

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.


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.


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.

Tuesday, May 17th 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:

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.
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.

And of course, there is always the saying that girls steal some of their mother’s beauty.
So then I show them this:

From Helle et al 2002.

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).

From 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.

From Hrdy 1990.

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.


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