Is Your Brain Pink or Blue?

A new book by Lise Eliot, a neuroscientist at Rosalind Franklin Institute of Medicine, examines the role that very subtle differences in parents' expectations may create differences in brain development of boy and girl babies.

According to an article about Pink Brains, Blue Brains in Newsweek, many studies show that parents' expectations for gender-based behavior or competencies can lead to reinforcing those tendencies in kids.

For example, in a study where people were told that male newborns were female and vice versa, they rated the "male" babies as more irritable.

I haven't read the book, but the Newsweek article points up a bit of a contradiction. Eliot may be saying that all the differences in adult brains can be tied to differences in nurturing, but the article itself contradicts that:

For instance, baby boys are more irritable than girls. That makes parents likely to interact less with their "nonsocial" sons, which could cause the sexes' developmental pathways to diverge. By 4 months of age, boys and girls differ in how much eye contact they make, and differences in sociability, emotional expressivity, and verbal ability—all of which depend on interactions with parents—grow throughout childhood. The message that sons are wired to be nonverbal and emotionally distant thus becomes a self-fulfilling prophecy.

This makes sense, except ... we're starting with, "baby boys are more irritable than girls." If this is the case, then it implies that there is an innate difference, perhaps because of the greater testosterone in the male baby's brain and body. 

I can certainly buy a theory that nurture can enhance these innate differences. But I have to agree with Michael Gurian (and a lot of science) that the differences in the amounts of testosterone and estrogen in a baby's brain guide neurodevelopment, especially in the first three years of life, when the neurons are forming connections that will last throughout our lives.

Gurian, authof of a series of excellent parenting books, including The Wonder of Boys, put out a press release saying,

It seems that most of the world already senses that boys and girls are inherently different (albeit on a vast spectrum, not stereotypes), but some people still fear this human experience, or aren't sure what to make of it.   Unfortunately, these books/articles select evidence and don’t take into account brain scans and other hard science; and they extrapolate the effect of socialization on formation of gender in the brain. For instance, PBBB provides a study of children who are encouraged to climb a hill a certain way and extrapolates that because there were differences in how parents talked to boys/girls, this could somehow account for the profound differences that show on PET and SPECT scans between girls and boys' brains.

He also posts some research on his site showing gender-based differences in the brain.

This is an argument that won't be resolved any time soon. It's important for parents to think about this and do what they can not to reinforce crippling gender roles on kids of either sex. For our grown-up relationships, I still think that looking at our emotions and interactions through the lens of neurochemistry can provide insight and comfort.


Did Nature Design Women to Be Social Leaders?

Oxytocin seems to be the key to flocking behavior in birds, as well as schooling behavior in fish. And these behaviors seem to be led by female populations. Could it be that human females are biologically wired to provide the foundation for social behavior?

James Goodson of Indiana University found that blocking mesotocin, an avian neurochemical similar to oxytocin, in zebra finches changed their social behavior. According to the press release,

They spend significantly less time with familiar individuals and more time with unfamiliar individuals. The birds also become less social, preferring to spend less time with a large group of same-sex birds and more time with a smaller group. Conversely, if birds are administered mesotocin instead of the blocker, the finches become more social and prefer familiar partners.


But Goodson found that blocking mesotocin only affected the females; the males' behavior was unchanged. He also found that whether a species likes to congregate seems to depend on the location of the mesotocin receptors.

In the news article, Goodson doesn't speculate on why oxytocin and mesotocin are so much more potent in females. He says he hopes more work on songbirds will shed light on the question. But it's my understanding that, in humans, estrogen enhances the bonding effects of oxytocin, while testosterone mutes them. So it makes perfect sense that women -- in general -- are more interested in social connection.

Putting this together with Goodson's work on flocking, it could be that the predilection for bonding goes beyond individual connections. Perhaps women, like female zebra finches, influence society as a whole, helping us to cooperate, collaborate, trade and keep peace.

The paper, published last Friday in Science, is Mesotocin and Nonapeptide Receptors Promote Estrildid Flocking Behavior.


Chip August's Sex, Love & Intimacy Podcast

Charles August, or Chip for short, has done 90 podcasts covering all aspects of sex and love for Personal Life Media (a company founded by internet wundergrrrl Susan Bratton). Chip co-facilitates, with his life-partner, a relationship workshop for couples called Passionate Relationships. Chip is also a certified Instructor of PET (Parent Effectiveness Training) leading adult education workshops to teach listening, conflict resolution and communication skills to parents.

I was honored to be Chip's 90th guest recently.

We talked about how the way we're mothered influences the way we love as adults, and how that plays out in our relationships throughout life.

You can listen to the podcast via iTunes or here on Personal Life Media. If you're an old-fashioned readerly type like me, you can also read the transcript when you click on that link.

Thanks, Chip!


Love Styles and Oxytocin

I use the phrase "love styles" to refer to the concept of attachment styles put forth by John Bowlby and Mary Ainsworth. Ainsworth developed a test, the Strange Situation, to see what kind of relationship babies had with their mothers. They came up with three: Secure, anxious or avoidant attachment. Some psychologists have create subcategories or changed these a bit. But the basic theory is, you can be securely attached to your mother, you maybe anxious that she's not going to be there for you, or you can be so scared or hurt that you withdraw into yourself and try not to need anyone else.

I believe that you can also look at these as oxytocin styles. Because the way our brains release and react to oxytocin is shaped by our earliest experiences,  these love styles are likely the result of the way that the  oxytocin response developed.

I'm fascinated by this kind of thing, because understanding it helps me understand myself and my relationships.

This is a long-way-round introduction to my interview with Deb Harper  of Psychjourney. Deb creates podcasts with authors, psychologists and thinkers on psychological topics. We talked about attachment styles and oxytocin in the wide-ranging interview. The conversation was very interesting for me, and I hope you'll think so, too.

CORRECTED: You can download the Chemistry of Connection podcast here.


Oxytocin Better than Beer for Hooking Up?

Okay, I am being facetious. But a new study found that inhaling oxytocin made study subjects feel more positively about strangers.

ABC News reported on the study by Angeliki Theodoridou, a psychologist at the University of Bristol, UK. This makes sense, because oxytocin has previously been shown to reduce activity in the amygdala, the part of the brain that makes pre-conscious, friend-or-foe decisions. Oxytocin seems to act as a trust signal, letting us gradually approach other people.

Theodoridou was on the team led by Eric Hollander that found oxytocin reduced symptoms of autism and increased adult autistics' ability to detect emotional meaning in speech.


Oxytocin Cools Marital Spats

Inhaling oxytocin helps couples fight fair, a new study shows.

When couples sniffed oxytocin and then engaged in a mock argument, those who'd inhaled the good stuff showed more positive communication and engaged in less negative behaviors. They also had lower levels of cortisol, indicating they didn't get as stressed out by the fight. The study was led by Beate Ditzen under the aegis of Markus Heinrichs, the University of Zurich scientist who did the original human oxytocin studies.

I reported on an earlier study by Bitzen that showed the same results: Oxytocin Keeps the Lid on Spats. Also, Adam Guastella in Australia, is studying the use of oxytocin inhalants as an aid to couples therapy.

The article is "Intranasal Oxytocin Increases Positive Communication and Reduces Cortisol Levels During Couple Conflict" by Beate Ditzen, Marcel Schaer, Barbara Gabriel, Guy Bodenmann, Ulrike Ehlert, and Markus Heinrichs. Authors Ditzen and Ehlert are affiliated with the Department of Psychology, Clinical Psychology and Psychotherapy, University of Zurich, Zurich, Switzerland. Ditzen is also with the Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia. Schaer, Gabriel, and Bodenmann are from the Department of Psychology, Institute for Family Research and Counseling, University of Fribourg, Fribourg, Switzerland. Heinrichs is affiliated with the Department of Psychology, Clinical Psychology and Psychobiology, University of Zurich, Zurich, Switzerland. The article appears in Biological Psychiatry, Volume 65, Issue 9 (May 1, 2009), published by Elsevier.

Luckily, Elsevier's PR person gave this a better title: Love Potion #1?


Take the Passion Poll

Passion coach Eryn-Faye has posted three polls on her blog.

How often do you go on a date with your spouse?

How often do you and your SO talk about sex?

Who initiates sex more often?

All good questions anyone in a relationship should be thinking about. Go to Eryn-Faye's blog and take the passion poll, then see how other people answered.

I think my basic answer is "not often enough."


I Heart Pepsi

I have a theory that advertising and brand messages can evoke the oxytocin response in us humans. This hasn't been validated by science yet, but it makes sense. Sociologists talk about parasocial relationships, that is, relationships with people we haven't actually met, such as celebrities or fictional characters.

Fans express their desire and love for characters in TV shows in the same way as they might talk about a real person, and they sometimes cry real tears over fictional events. So why would their love be less real -- or less oxytocin-producing?

I ran across this December 2008 article in Science Daily that provides another piece of evidence. Vanitha Swaminathan, Karen M. Stilley (University of Pittsburgh), and Rohini Ahluwalia (University of Minnesota) found that someone's attachment style influenced their reactions to brands.

The kind of bond we have with our mother -- the way our oxytocin response forms -- depends on how she treats us. We then tend to apply the mode of loving we learned from her to our future relationships. Psychologists group them into three or four "attachment styles."

From the article:

According to the authors, anxiously attached individuals are more influenced by "brand personalities," the idea that a brand possesses humanlike traits, such as sincerity or excitement. "Because of a low view of self, anxious individuals use brands to signal their ideal self-concept to future relationship partners and therefore focus more on the personality of the brand," the authors write.

What this says to me indirectly is that our attachment to a brand uses the same brain circuits and neurochemistry as our attachment to another human. So brand loyalty is a kind of love that's as real as any other.


Serotonin Makes a Happy Crowd

Swarming locusts are famous for devouring everything in their path. Looking for the trigger that makes billions of locusts form one of these devastating hordes, scientists discovered that serotonin turns the usually solitary grasshoppers into highly social -- and highly mobile -- insects.

When there's plenty of forage, locusts are solitary, happily going about their business eating and pooping. As resources dwindle during dry periods, the locusts get more and more crowded and come into physical contact with each other. However, instead of this crowding triggering fighting and increased competition, it instead causes them to be more social. They actively seek each other out, according to this article from ScienceDaily.

The research team found that they could easily make solitary locusts gregarious simply by tickling their hind legs, which simulates the jostling they'd get in the wild. This tickling caused a jump in serotonin in the locusts' brains, which happen to be located in their thoraxes.

According to the story:

Dr Swidbert Ott, from Cambridge University, one of the co-authors of the article, said: "Serotonin profoundly influences how we humans behave and interact, so to find that the same chemical in the brain is what causes a normally shy antisocial insect to gang up in huge groups is amazing."

Professor Malcolm Burrows, also from Cambridge University: "We hope that this greater understanding of the mechanisms causing such a big change in behaviour will help in the control of this pest, and more broadly help in understanding the widespread changes in behavioural traits of animals."

Animals like people? Okay, and why am I covering this in a blog about oxytocin?

The oxytocin and serotonin systems are closely related, and both neurochemicals seem to influence social behavior. Low-serotonin monkey mothers aren't as nice to their babies, and lower levels of mothering behavior in mice create fewer oxytocin receptors in the brains of their pups -- even when they grow up.

It's likely that both of these hold true for humans; and evidently these researchers think their locust research could apply to mammals.  Connecting the dots:

Could we be an under-nurtured, low-serotonin, low-oxytocin society? Could this by why we can no longer come together as a unified society, but instead get more stressed out and angry, the closer we get?

University of Cambridge (2009, January 29). How A Brain Chemical Changes Locusts From Harmless Grasshoppers To Swarming Pests.

See also: Oxytocin Deficit Disorder


The Monogamy Gene

Researchers at the Karolinska Institute found that variations in a gene for vasopressin correlate with monogamous tendencies. Vasopressin seems to influence some bonding behaviors in males; it's  influenced by testosterone; and it's also responsible for defensive and aggressive behaviors, often in defense of the mate and family.
According to Bloomberg Muse:

The researchers ran genetic tests on 2,186 participants in the Twin and Offspring Study in Sweden and had them fill out a survey about the quality of their marriage. Men with a genetic variation scored significantly lower on a scale of partner bonding. One in three reported a crisis in their marriage within the past year, twice the number as those without the variation.

... Those whose husbands had one or two copies of the gene variation scored significantly lower on tests asking about their marriage quality than those without it.

Larry Young and Elizbeth Hammock of Emory University had found that variations in parts of the vasopressin gene, formerly considered "junk DNA", seemed to influence monogamy in the prairie vole. While this rodent is socially monogam0us, some individuals never mate. Hammock was able to breed non-monogamous prairie voles by selecting for this variation.

I heard Young present about this at a conference, and he was very cautious about extrapolating his vole work to humans. Paul Lichtenstein, a professor of genetic epidemiology at Karolinska, has kindly connected the dots for us humans.