Science of Love, Sex, and Babies

Who’s Turned On By Pregnant Women?

Posted in parenting, pregnancy, psychology, science, sex by jenapincott on September 26, 2011

 

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 theat animal reaches sexual maturity. For instance, goats that are raised by sheep are sexually aaroused 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. Interstingly, 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. 

 

 

 

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A Kirkus Star!

Posted in book reviews, parenting, pregnancy, science by jenapincott on September 8, 2011

Absolutely delighted that Kirkus gave “Do Chocolate Lovers Have Sweeter Babies?” a starred review. Thank you, Kirkus!
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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.

Do Beautiful Babies Become the Most Beautiful Adults?

Posted in pregnancy, psychology, science by jenapincott on August 18, 2011

The Gerber baby, then and now

Forgive me, I believe my one-year-old is the cutest baby ever. Yes, yes, mothers are biased about their own children.  As I detail in my new book, certain reward circuits “light up” in parental brains only when looking at their own offspring.  But objectively — objectively! — my daughter is adorable.

The little one has “Gerber baby” features:  a bulbous forehead, big eyes, luscious cheeks and thighs (and curls). Babies with these qualities are rated as cuter than those with sunken foreheads, small eyes, and large or long chins.  Adults smile and gaze longer at them. Attractive infants are perceived to be more sociable, easier to care for, and more competent than their homely peers. They inhibit aggression in adult men. They receive more nurture.

Our baby thrills to the attention, and my husband and I have started to worry that being cute might not lead to anything good.  I have a theory that ugly ducklings and tomboys grow up to have richer inner lives.  I don’t want a princess.

We want to know:  Do the cutest babies turn out to be the most attractive adults?

Conveniently, a recent study by psychologists Gordon Gallup Jr, Marissa Hamilton, and their colleagues addresses this very question. (I love these whimsical studies; they’re motivated by genuine curiosity.) The presumption is that physical attractiveness remains stable over time.  This has been proven in childhood onward:  attractive ten-year-olds are likelier to be attractive adults.  (Another study found that adult attractiveness can be predicted as early as age five).  But until now no study had tracked attractiveness from infancy.

It’s interesting, how the psychologists went about it.   They sifted through high school yearbooks and found forty graduating seniors who featured photos of themselves as infants. Then they asked several hundred college students to rate the the individuals — in infancy and in adulthood — for attractiveness.

The upshot?

There was no correlation between attractiveness in infancy and (young) adulthood. Some ugly ducklings turned into swans, some baby swans become ugly ducks.  Some gawky, awkward babies remained that way into their senior year of high school.  And some beautiful babies kept their glow through the years. This was true of males and females alike.  Cuteness — or homeliness — in infancy does not predict future attractiveness.

The study included an interesting side finding:  While the raters were likely to agree about which infants were attractive, they often disagreed about which eighteen-year-olds made the cut. Why? The gold standard of baby beauty — the forehead, the eyes, the thighs — is universal. These preferences are hard-wired in us to elicit care and protection, while the perception of adult beauty is tempered by culture.

Cute babies are universal positives.  In this light, it’s OK that mine gets attention now.  The future will be much less predictable.

 

 *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, Do Chocolate Lovers Have Sweeter Babies?: The Surprising Science of Pregnancy. 

 

Do You Live Less if Your Mom Was Stressed?

Posted in parenting, pregnancy, psychology, science, sex by jenapincott on August 12, 2011

Not long ago, a handful of scientists at the University of California at Irvine were curious about why some people live longer than others — even within groups that have similar ethnic and educational backgrounds, demographic and disease risk profiles, and are exposed to similar stressors in life.  At heart, they know the question is impossible to answer.  People are complex. The effects of life events on our genes—what we eat, what we breathe, who we love and how well we’re loved, and so on —are impossible to isolate.

But the scientists had a hunch that some of us had a bad start —beginning in the womb — because our mothers were highly stressed during pregnancy.   There’s an avalanche of evidence that women who are under extreme duress in pregnancy have kids who have shorter attention spans, lower IQ, memory deficiencies, and health problems.  

Could prenatal stress also set a baby’s life expectancy clock to tick faster?

One way to find out is to look at the genes of people whose mothers were extremely stressed during pregnancy. In each of our cells are DNA-protein complexes called telomeres, which cap the end of chromosomes.  Telomeres are like the plastic bit at the end of a shoelace to keep it from unraveling. Each time a cell divides, they become a little shorter. This makes telomeres something of a longevity marker. People with long tips at the end of their DNA strands tend to live longer than people who have short tips.  It doesn’t matter how long your shoelace is; what counts is the integrity of the cap.

In the UCI study, researchers recruited volunteers in their twenties. Some were selected because their mothers experienced a horrid event during pregnancy.  The scientists weren’t looking for the normal pregnancy stressors — work-life balance, weight gain, fretting about the baby’s health, and so on. They meant extreme stressors: a sudden divorce, a death in the family, a natural disaster, and physical or emotional abuse.

What they found is disturbing.

Compared to the control group (whose moms had a relatively stress-free pregnancy), people exposed to their moms’ extreme prenatal stress had significantly shorter telomeres.  By our mid-twenties, most of us lose about 60 base pairs of telomere length annually.  Not so of people who were exposed to extreme prenatal stress — they lose drastically more telomere length each year. The men had 178 fewer base pairs on average (equivalent to 3.5 additional years of aging).  Women had a shocking 295 base-pair deficit  (5 years of accelerated aging). It seems that a mother’s prenatal stress hits her daughter harder than her son.

How does this happen?  During pregnancy, stress may alter blood flow, oxygen, and glucose metabolism between mother and baby. High levels of the stress hormone cortisol from the mother flood the placental barrier. Excess cortisol may also slow down in the production of telomerase, an enzyme that acts as a repair kit for telomeres. Telomerase adds telomeric DNA to shortened telomeres. It regenerates our cells and tissues.  Like a fountain of youth, telomerase gives back what time takes away.

So what if you’re on a telomerase-less trajectory?

Here’s the big relief:  Your clock doesn’t have to keep ticking so quickly, even if it has been set that way before birth. There’s strong evidence that lifestyle changes can amp up telomerase production. One study found that stress management, counseling, and a healthy diet are associated with higher telomerase activity.  Another found that meditation turns up the telomerase dial.  

In the research community there’s much interest in the idea that, by maintaining our telomeres, gene therapy might someday reverse or prevent aging if started early enough.  Is it possible? As a measure to conceal the abuses of youth, teens could freebase on telomerase. 

Oh, the ways to stress out Mom.

 

 *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, Do Chocolate Lovers Have Sweeter Babies?: The Surprising Science of Pregnancy. 

 

Assorted Trifles (from the science of love, sex, and babies)

Posted in news, parenting, pregnancy, psychology, science, sex by jenapincott on August 4, 2011

Research is like a box of chocolates; you never know what you’re going to find. An assortment of studies on love, sex, and babies — fresh from the lab.

Scientists found that men whose ring fingers are longer than their index fingers are likelier to have longer-than-average penises, at least among Korean men whose flaccid genitals were stretched under anesthesia. Studying the files of women who were raped in 1999-2006, French researchers discovered that there were fewer incidences of living sperm than in rape victims in previous generations, which supports the theory that sperm quality is declining. Women are likelier to get pregnant if they ovulate from their right-side ovary, visible by ultrasound, especially after two consecutive left-side cycles, inspiring women undergoing fertility treatment to desire a L-L-R pattern. Among women whose fetuses inexplicably died in third trimester, 64 percent (392/614) had a premonition before their doctors told them. They described a feeling of discomfort, of a strange unease; that they understood subconsciously that the baby would die. Many described how they dreamed of dead relatives and of death on the night the baby probably died. A recent fMRI study reported that women who had given birth vaginally exhibited greater activation in brain regions involved in the regulation of empathy, arousal, motivation and reward circuits in response to their baby’s cries compared to those who had not. Women who snore loudly and frequently were at high risk for low birth weight (relative risk = 2.6 [95% confidence interval = 1.2-5.4]), and fetal-growth-restricted neonates. The success of an IVF transfer may in part be predicted by how much glucose medium an embryo “eats” on days 4 and 5. On Day 4, female embryos consume significantly more sugar than males.

Publishers Weekly — First Review for Chocolate Lovers!

Posted in book reviews, magazine articles, media, news, parenting, pregnancy, science, sex by jenapincott on August 4, 2011

My first review for Do Chocolate Lovers Have Sweeter Babies?, from this week’s Publishers Weekly.

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Do Chocolate Lovers Have Sweeter Babies: Exploring the Surprising Science of Pregnancy
Jena Pincott. Free Press, $15 trade paper (256p) ISBN 978-1-4391-8334-2
Science writer Pincott (Do Gentlemen Really Prefer Blondes?) began her research when she was pregnant; her daughter was born during the writing process, and she describes the work as “curiosity -driven,” urging readers to flip to the pages that interest them most. As Pincott negotiates her pregnancy, she explores a wide array of subjects expectant parents will find utterly captivating, drawing from studies in evolutionary psychology, biology, social science, neuroscience, reproductive genetics, endocrinology, and largely from research in the field of epigenetics, the influence of environment on the behavior of genes. She examines each phase of her own pregnancy, addressing odor and taste aversions (the “gag list”), vivid dreams, how diet affects a gene’s behavior, and a wealth of other subjects. She delves into how dads react to pregnancy (many put on weight) and makes the remarkable observation that what grandma ate when pregnant way back when may influence the baby’s future health (“I’m eating for two generations,” she quips). While readers will be entertained and fascinated by this text from start to finish, the concluding chapter, “Lessons from the Lab,” offers expectant mothers a valuable summary of practical research-based tips (moderate stress experienced by mom may actually be good for the fetus; eating a chocolate bar a day may improve baby’s temperament). Pincott writes with humor and vibrancy, bringing science to life.

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