Check out my video and excerpt from Chocolate Lovers on Big Think.
This is not an ad in the personals. It’s the opening line of the commentary in the straitlaced scientific journal, Proceedings of the National Academy of Sciences (PSAS). The authors, neuroscientists Liisa Galea and Cindy Barhain, intend to shock. Why, one wonders, would a man have no luck in love?
Findings from a new study suggest it may be your mother’s dietary exposure to bisphenol A (BPA).
Galea and Barha have all my attention now. Ever since my pregnancy, I have been tracking studies on BPA’s subtle yet shocking effects. One of the most common chemicals in the world, bisphenol A is found in the stuff we use every day of our lives. Soup and soda cans. Water pipes. Computers. Cell phones. Thermal paper receipts. Paper money. Even some baby bottles—at least in the U.S., because they are not banned here.
Much of the trouble with BPA lies in its ability to fool estrogen receptors into thinking it’s estrogen. Imagine a man doesn’t know that the woman he’s marrying is really an alien in drag, and you have a sense of the danger here. BPA disrupts any process that estrogen normally mediates, affecting brain, body, and behavior. It also tinkers with the way genes express themselves, turning up those that would otherwise be turned off or down. BPA exposure has been linked to breast cancer, heart disease, obesity, diabetes, attention-deficit disorder, increased anxiety, a decreased IQ in children and a low sperm count in men.
Pregnant women and new moms should be especially cautious. BPA has been found in umbilical cord blood and in breast milk. It crosses the placenta and flows in fetuses. Young bodies are especially vulnerable to pseudoestrogens. The toxin strikes us moms, too. Researchers worry that BPA may affect women’s brains in a way that alter their maternal instincts. In laboratory studies, BPA-exposed female rats are less likely to nurture their offspring—they lick them less—which in turn affects the emotional and cognitive system of their babies. They become more fearful and anxious.
And now, there’s more.
There is evidence that BPA emasculates males and makes them sexually undesirable. Galea and Barha’s opening lines in PSAS are tongue in cheek—they are describing a new study at the University of Missouri on the effects of BPA on deer mice—but the application to humans is implicit. Adult mice whose mothers were fed a dosage of BPA equivalent to what the USDA deems safe for pregnant women, were, well, different from other males.
“One of the prominent effects of early BPA exposure is that it eliminates a number of sex differences in brain and behavior,” the researchers wrote. It turned out that BPA-exposed males have impaired spatial ability (can’t find their way out of a maze or to their nest, considered unattractive to females). They also suffer from decreased exploratory ability (incurious and easily lost), and overall reduced attractiveness to the opposite sex. They may even smell different from their peers—in rodents, a sign of unhealthiness. Females are disgusted.
It’s not absurd to worry about similar effects of BPA-exposure on our babies. Men are not mice, but there is increasing evidence that BPA affects us as well, and in doses below the below the 50 µg/kg/day safety threshold in the United States. Almost every American pregnant woman (93 percent) has detectable BPA in her body, which is passed on to her fetus. The average BPA body burden of an American is high, alarmingly high, compared to other countries. We love our BPA-enriched Cokes and canned Campbell’s soups.
On a population level, how might BPA affect us? Might boys in the U.S. grow up to have poorer spatial skills—and, because it’s linked, weaker mathematical ability? Might they have little interest in exploring the world, preferring to hang out at home? Might our national temperament become more placid? Because BPA is lined with obesity and heart disease, will we become fatter and more sedate? And what about our sex lives?
Take a look at human history through the lens of hormones, as Harvard University’s Daniel Lord Smail did in his fascinating book, On Deep History and the Brain. Smail introduces a new view in which physiology and culture evolve symbiotically in a process driven by brain chemistry. Caffeine stimulated the body and mind, driving the industrial revolution and the modern corporation. Tobacco help us to focus and be calm. These substances changed the character of society. Now we have environmental toxins such as BPA (and other hormone disruptors such as phthlates and PCBs) that may also change our culture in subtle but very real ways.
BPA: Bad for your manhood. Bad for your sex life. Sensationalistic, sure—but would this get CEOs to pay attention? Hit them where it hurts.
Stubborn pushback—that’s the response from many corporations regarding BPA bans. The chemical is a mainstay in packaging, and to ditch it is disruptive for business. Coca Cola has famously refused to find an alternative. You can find BPA-free cans of beans from brands such as Eden, but not crushed tomatoes yet (in the meantime, buy them in glass jars). Avoid plastics that are marked with recycle codes 3 or 7; they may contain BPA. While Canada, Europe, and even China have banned the use of the chemical in baby bottles, the U.S. has not (although consumer demand has pushed many manufactuers to go BPA-free).
The good news, as I describe in my book, is that there is laboratory evidence that a diet high in folic acid and B12 may reverse at least some of the nasty effects of prenatal BPA exposure. How? One way that BPA tinkers with our systems is by attaching itself to strands of DNA and “turning on” certain genes (removing methyl groups) that are normally turned off—resulting in obesity, cancer, and other nasty effects. This is classic epigenetics—an environmental trigger affects the way that genes behave. Nutrients in green vegetables, beans, eggs, and soy may be protective (in those of us who include enough in our diet) because they turn off genes that BPA otherwise turns on.
Of course, the best protection is to turn corporations off BPA. That would really be a turn-on for us moms.
*If you like this blog, click here for previous posts. If you wish, check out my new book, Do Chocolate Lovers Have Sweeter Babies?: The Surprising Science of Pregnancy.
Check out in BOING BOING one of my favorite excerpts from Chocolate Lovers — on the very weird science of what fetal cells do in mothers’ bodies.
The best holiday gift: DO CHOCOLATE LOVERS HAVE SWEETER BABIES gets a STARRED REVIEW in Library Journal! Many thanks to Library Jrnl and the reviewer, Julianne Smith.
What a charm! Science writer Pincott (Do Gentlemen Really Prefer Blondes?) tackles some myths and legends associated with pregnancy and compares them to peer-reviewed research on the matter. The book covers such questions as: “Do men prefer babies who resemble them?” “What does a baby’s birth season predict?” and “Do bossy broads have more sons?” This is an enjoyable, insightful, and fascinating look at pregnancy that explains what we know and identifies what we don’t. In discussing topics from stretch marks to mama’s boys, Pincott takes a conversational tone, making the science readily available to all readers. An ideal acquisition for public libraries, a great gift for expectant parents, and the perfect choice for the doctor’s waiting room, this winning title deserves some talking up. Way more fun than What To Expect.
Today I was thrilled to see a mention of Chocolate Lovers in one of my favorite parenting sites, Urban Baby.
For women trying not to get pregnant, life should be easy. Conception can only happen 12-24 hours after ovulation. Sure, sperm may last as many as 3-4 days in the genital tract, hanging around for the egg to arrive. But you’d think that, to avoid a pregnancy, all you’d have to do is to abstain from sex for 4-5 days around the ovulation window.
That’s what the rhythm method is — a natural form of birth control that relies on abstinence during a woman’s fertile days.
But slips happen even among the most careful practitioners of the rhythm method. Some of this may have to do with women not keeping perfect track of their menstrual cycles or having naturally irregular cycles. The failure rate for rhythm method is 25 percent each year (with a perfect-use the rate is still nearly 10 percent).
This is shockingly high. Why so high?
The hidden reason could be pheromones, chemical signals that subtly influence our behavior with out our knowing. It’s just speculation in the journal Medical Hypotheses, but it’s worth mentioning. The submission suggests that pheromones that men put out in their sweat and saliva may trigger early ovulation in women. This phenomenon has been observed in other studies, including this one at the Monell Chemical Senses Center. The early release of the egg — in advance of the expected fertile window — obviously increases the chances of fertilization.
The target chemical is androstadienone, a testosterone-related compound. It’s not only in men’s sweat, but also in their semen and saliva. Androstadienone works its charm by increasing the amount of luteinizing hormone in women, which thereby triggers ovulation. Women inhale the chemical in men’s sweat (or absorb it orally or vaginally), whereby it acts on their hypothalamus, the region of the brain that controls hormone secretion.
It’s possible that high-testosterone men — who produce more androstadienone — may be likelier than low-tesosterone men to have an accelerated-egg release effect on their lovers. Their sweat smell alone may do the trick.
As I mentioned in a previous post, there are other properties in semen that may also trigger early ovulation. For instance, seminal fluid contains follicle stimulating hormone (FSH) and luteinizing hormone (LH), which may coax the ovary to release an egg.
Bottom line: there are many events that may throw off a woman’s cycle. We don’t live in a clockwork universe, nor do we have clockwork bodies.
Note: A previous version of this post contained a reference to NFP, the Catholic Church’s form of birth control. NFP techniques such as cervical mucus and basal temperature readings, etc. are much more reliable than the rhythm method.
*If you like this blog, click here for previous posts. If you wish, check out my new book, Do Chocolate Lovers Have Sweeter Babies?: The Surprising Science of Pregnancy.
For months I’ve had a hunch that having a baby has been better for my husband’s image than mine. I don’t mean his looks. Neither of us has had much time to sleep and shower and pay attention to clothing and hair. What I mean is that I think first impressions favor fathers more than mothers. Pushing our baby along in the stroller, holding a coffee cup and singing, I fall into an easy stereotype, but my husband doesn’t. Yes, in terms of public image, I believe a man benefits more from being a father than a woman benefits from being a mother.
Am I right?
A couple years ago, Ariane Kemkes, a researcher at the Tholius Institute for Research in Applied Demography in Scottsdale, Arizona, asked the same question. Kemkes wondered what would happen if you took a picture of a parent sitting next to his or child, and impartial judges rate that parent in terms of attractiveness, smarts, success, and so on. Then, she wondered, what would happen if you crop the child out of the photo and ask a different set of judges to rate them on the same criteria?
Are men and women judged differently when they’re with kids than without? And if so, do fathers benefit from a bigger boost in their social image than do mothers?
The results are intriguing to us new parents.
Men perceive mothers and fathers differently than women do. Looking at a photo of mother and child, male judges are 2.4 times more likely than female judges to believe that the woman is committed to family. Female judges were more cynical and critical of other women’s maternal commitment (but more interested in meeting them). Surprisingly – and to my relief – both sexes are marginally (1.1 times for men, 1.2 for women) more likely to think a woman looked more attractive with a child than when she was alone. Men, however, were more ambivalent abot meeting women if they were mothers. A mother was also perceived by judges of both genders as slightly, but not significantly, more faithful, honest, and mature.
But what about her mind? Here comes the crux of my argument about the drawbacks of motherhood. If a woman was paired with her child, both male and female judges perceived that woman to be less ambitious than if she was alone. The presence of a child around a woman reduced the woman’s likelihood of being regarded as ambitious by as much as 30 percent. The assumption by men is unsurprising, but that the stereotype is held by other women is startling. The results may make one pause on bring-your-child-to-work day.
And now, what about men — what does fatherhood do to their image?
Only good things, as I presumed.
Men with children were perceived by all as being committed to family. Interestingly, fatherhood was good for a man’s social life. Men were 1.2 times more interested in meeting fellow a man with a child than the same man without a child. And here’s another perk of fatherhood: A man with a child is perceived to be of a higher social status. This comes from judges of both genders. Fathers are also believed to be more faithful, mature, honest. They’re also thought to be more generous – a perception not transferred to women with children.
Kemkes sums up the stereotype: females most often associate maternity as conflicting with career and leisured activities, while males emphasize financial sacrifices. A childless woman is perceived as ambitious and a childless male is perceived as cash-strapped, immature, or having a lower social status. For men, there is a strong association, explainable in evolutionary terms, between reproductive and financial status that does not exist for women.
Moreover, as Kemkes points out, men who are fathers are perceived as more generous than their childless counterparts because emotionally unstable men are more possessive and monopolize resources – traits not associated with fatherhood. Being a dad makes a man appear more “prosocial”; that is, generous and willing to cooperate. Men are likelier to want to meet dads than childless men because fatherhood lowers expectations of inter-male competition. It’s now established that fatherhood is linked to lower testosterone levels, especially in the first months after a baby’s birth.
There’s a lesson in research of this kind. While parenthood generally boosts the social image of both genders, it still cripples career women more than men. Although more fathers are taking care of the their kids while the mother goes to work, the stereotype that mothers aren’t as ambitious still hasn’t budged – in part, perhaps, because many workplaces continue to make it difficult to excel in both. So the disappointing fact remains: A man who prominently features a photo of himself with his children on his desk at work is doing more for his career than a woman who does the same.
*If you like this blog, click here for previous posts. If you wish, check out my new book — hot off the press! — Do Chocolate Lovers Have Sweeter Babies?: The Surprising Science of Pregnancy.
A nice review for Chocolate Lovers in today’s Boston Globe
Early one evening late in my second trimester of pregnancy, I was standing in the dairy aisle of the grocery store, with one hand on my back and the other over the kicking baby in my distended belly. A young man approached me, initiated a conversation about the World Cup, and, casually, asked me if I’d like watch the game with him that weekend. “You’re pretty!” he whispered. I was shocked.
I wasn’t putting out a sexy vibe. (Not at all.) I had assumed that any male attention I receive in late pregnancy, including that from my husband, would be friendly, not sexual. Why would a man who is not the expectant father think pregnancy is sexy? But then other women told me similar stories about how they got hit on in third trimester. So I decided to look into it, and it turns out that a study on sexual attraction to pregnancy has recently come out.
A team of Swedish and Italian doctors, led by Emmanuele Jannini and Magnus Enquist, recruited nearly 2,200 men who had joined online fetish groups such as alt.sex.fetish and alt.sex.fetish.breastmilk. They presented a questionnaire that asked the respondents questions about their preferences for pregnant and lactating women. The survey also asked for the sex and age of each sibling, and whether the sibling is a full sibling or not (half-sibling or adopted child). Most respondents reported both a pregnancy and a lactation preference. The average age at which respondents became aware of their preference was about 18 years.
What Jannini and Enquist and their colleagues were searching for was evidence that there was something special about the upbringing of men that are secually aroused by pregnancy. They knew that a specific stimulus early in life can elicit sexual behavior when that animal reaches sexual maturity. For instance, goats that are raised by sheep are sexually aroused by sheep only. This is called sexual imprinting.
Is it possible that boys that are raised by women who are pregnant for much of their childhoods are unusually attracted to pregnant women?
It turns out, what’s good for the goat is good for the guy. The more exposed a man was to his mother being pregnant and breastfeeding when he was between 1.5 and 5 years old, the more likely he is, as an adult, to be sexually attracted to pregnant and breastfeeding women.
A younger sibling is the key to early exposure. The respondents who eroticized pregnancy and breastfeeding had significantly more younger siblings than expected by chance. Respondents with one sibling were older than their sister or brother in 66 percent of cases. Interestingly, siblings born of a different mother does not appear to be related to respondents’ sexual preferences. Only a boy’s own pregnant mother seemed to leave a sexual imprint.
Freud’s “oedipal phase,” from about 3 to about 5-6 years of age, only overlaps partially with the sensitive period suggested by this study’s data, the researchers are careful to point out. Sexual imprinting is different in that it’s motivated not by sexual drive but because the individual learns what’s normal during a sensitive phase of development and later seeks sexual partners that resemble his (or her) own parents.
What does this mean for women who are pregnant or plan to be pregnant? It means you may be able to predict how attracted your partner will be to you in late pregnancy. Does he have sibling born within five years after him? If so, he’s likelier to be turned on by your pregnant self.
As for the guy I met in the dairy aisle, I’d wager he had a younger brother or sister. I’d bet more on getting this right than the winner of the next World Cup.
*If you like this blog, click here for previous posts and here to read a description of my most recent book, Do Gentlemen Really Prefer Blondes?, on the science behind love, sex, and attraction. If you wish, check out my forthcoming book, available October 11, Do Chocolate Lovers Have Sweeter Babies?: The Surprising Science of Pregnancy.
Popular-science writer Pincott (Do Gentlemen Really Prefer Blondes?, 2008, etc.) provides a lively, accessible romp through the science of pregnancy.
Known for her previous research on love and sexual attraction, the author makes a natural transition in her latest. Delving into the science of pregnancy, parenthood and fetal development, she presents her findings with wit, personal anecdotes and playful humor. Eschewing predictable “avoid the shellfish” advice, Pincott provides a science-based trivia collection, drawing from studies in evolutionary psychology, biology, neuroscience, social science, epigenetics and more. She explores topics such as how a woman’s activities might influence her unborn baby’s personality, how pregnancy and motherhood can change the behavior of mothers and fathers, what factors might influence a baby’s gender and why the first hour after a baby’s birth means so much for mother-newborn bonding. Inspired by questions from her own first pregnancy, the author also digs up the answers to common inquiries such as “what does baby’s birth season predict?”; “what can Mozart really do?”; and “will what we eat now influence baby’s tastes later?” Despite the bombardment of information, Pincott presents her research as fun things to contemplate rather than additional things to worry about, so nervous expectant parents can thoroughly enjoy the book.
A fascinating supplement to the typical maternity guide.