Is males' attraction to trucks and balls genetically based?

 Young chimps. Photo: Delphine Bruyere 

My husband and I raised one girl and one boy, close together in age. We tried hard to avoid gender-stereotyping our young kids in any way. They had the same toys, many of them gender neutral, for some time.

Our son clung to the baseball fence, drooling
As it happened, our yard backed up to a school athletic field. From late winter on, we daily heard the THWOCK of  bats hitting balls during baseball practice. Our son was barely able to walk when he began toddling out to the playing field alone, to watch the students play baseball.  He'd hang on the baseball fence with his tiny fingers for hours, mesmerized and drooling. Soon he was into trucks - at the age of 2, he memorized the name of 33 different kinds of trucks from the truck library books he clamored for.  Our daughter's interests were varied, but she showed no inkling of his fascination with balls and trucks. We couldn't understand it. He wasn't in preschool, and my husband and I cared nothing for vehicles of any kind (although Ken is a baseball fan).

We share 98% of our DNA with chimps
So last week I was intrigued to see a paper in the online journal Current Biology about gender-stereotyped roles in young chimps. Since chimps are our closest relatives, sharing 98% of our DNA, any observations about chimp behavior could have implications for the origins of our own behavior.
 

Young female chimps "play mothering" more than young males

Author Sonya Kahlenberg, a biological anthropologist at Bates College in Maine, observed chimps in Kibale National Park in Uganda over 14 years. She and co-author Richard Wrangham, a biological anthropologist at Harvard, noted that 67% of young females carried sticks while only 31% of young males did. Sticks are used sometimes as weapons or as tools, to probe holes for food or water. But the young chimps also cradled long thick sticks as if a stick were a baby, carrying it around for no particular reason. They sometimes carried the stick as long as 4 hours, and took it with them to their nests for sleep. The authors felt that the stick-carrying was "play-mothering." The males who did it stopped as they got older. The females stopped when they gave birth to real babies, whereas use of sticks for other purposes continued after motherhood.

In her recent article, Kahlenberg cited previous research in which captive young male monkeys preferred wheeled toys, while female monkeys, like human girls, showed greater variability in preferences. The male monkeys also showed more rough-and-tumble play than females. The authors of this study (published in PubMed) hypothesized that these differences are hormonally influenced.

Some have speculated that boys, including some male primates, prefer toys like balls and trucks because these toys are associated with more freedom of movement than, for example, playing with dolls.

Evolutionary advantage for human males to prefer movement?
Could it be true that very young male humans are drawn to balls and trucks because playing with them involves more movement?  It's not clear at all to me that male attraction to movement would be more advantageous evolutionarily than female attraction to movement. Even while carrying infants, our female prehistoric ancestors still were compelled to move around gathering plants for food, I would think. And keeping up with mobile children certainly involves movement. But if males were the defenders of early human tribes, and if they went on long hunts for food, then perhaps males could have evolved a hormone-based propensity to be more active.

I don't know, it's an interesting question. Culture has so much to do with it. A few decades ago, girls rarely if ever participated in team sports at school (at least in the U.S.). Today they do, when given the opportunity.

One more reason to protect wild apes
I'd love to see more field observations of gender-based behavioral differences in young primates. That's one more reason we need to protect chimpanzees and other primates from the illegal poaching that threatens all populations of wild apes.

For more information about what you can do to protect wild apes, see these links to primate conservation NGOs:
Jane Goodall Institute
Orangutan Outreach
Sumatran Orangutan Society
Dian Fossey Gorilla Fund International
Orangutan Land Trust
International Primate Protection League
TRAFFIC:the wildlife trade monitoring network

Some of my previous posts about primates and primate conservation:
Hunting may threaten orangutans even more than habitat loss Dec 6, 2010

Wildlife trade rivals drug trade in profits September 20, 2010
Laws flaunted: flourishing pet trade threatens orangutans' survival August 23, 2010
My search for a wild orangutan in Borneo and Sumatra August 16, 2010
Orangutans dwindle as Borneo, Sumatra converted to palm-oil plantations August 3, 2010

The great apes are losing ground. March, 2010
The U.S. imports 20,000 primates per year. February, 2010
Baboons are Africa's most widespread primate. Females rule! December 30, 2009
Mama monkeys give in to tantrums....when others are watching. April 23, 2009
Angry chimp reveals a "uniquely human" ability. March 21, 2009

Monkeys and parrots pouring from the jungle. September, 2008
Chimps' short-term memory is better than humans'  April 2, 2008
Chimps share human trait of altruism August 3, 2007

Keywords: chimpanzees chimp behavior animal behavior gender stereotypes chimps and dolls chimps and sticks Sonya Kahlenberg Kibale National Park Richard Wrangham

Gender Stereotypes Hurt Hilary More than Racial Stereotypes Hurt Obama, Scientists Say

I've had enough of George Bush and his systematic un-doing of the environmental legislation enacted by the Clinton administration. I'm terrified at the prospect of another president who places corporate interests far above citizens' interests and way way way ahead of environmental interests.

I want a democrat yes, but this election has much more at stake then that. Our country will take a giant step forward, culturally and politically, if we can elect anyone who isn't a white male.

We've had 43 white males in a row as president. Right now, the ideal candidate would be a non-white female. But since that's not one of the choices, democratic voters will be choosing between a black male and a white woman to run against McCain.

I like Obama. What's not to like? He is reminiscent of the idealism and romance of the Kennedys, as everybody says. I have loved the Kennedys since I was a kid, and I still do greatly admire RFK Jr's prolific record of environmental accomplishments. When he wrote an endorsement for the jacket of our last book, I was so proud.

But....how can I not root for a candidate who is the first representative of my own gender to ever be a serious contender for the office of president? I pretended for awhile to weigh the merits of Obama and Hillary intellectually, and then one day, in one moment, it became crystal clear. I could never vote against Hillary. To do so, for me, would be a vote against women, against my own gender. Against this extraordinary chance that may not come for another 100 years.

If Hillary were not a woman, she would have bagged this nomination long ago.

In a country still beset by gender and race stereotypes, which one is more of a liability?

"Gender stereotypes trump race stereotypes in every social science test," says Alice Eagly, a psychology professor at Northwestern University.

Bias researchers such as Eagly have found that racial bias is strikingly changeable, and can be mitigated and even erased by everything from clothing and speech cadence to setting and skin tone.

Professor Eagly says that attitudes about women are harder to change.

Clinton's campaign has discovered for themselves that gender stereotypes are less changeable. Women can be seen as either ambitious and capable, or they can be seen as likable, but it's very unlikely for them to be seen as both. "The deal is that women generally fall into two alternatives: they are seen as either nice but stupid, or smart but mean", said Susan Fiske, a psychology professor at Princeton who specializes in stereotyping.

Although racial attitutes appear to be softening, there's little evidence that gender biases are.

Amy Cuddy, a psychologist at Northwestern, suggests the durability of gender stereotypes stems from the fact that most people have more exposure to people of the opposite gender than to people of other races. They feel more entitled to their attitudes about gender. "Contact doesn't undermine these stereotypes and it might even strengthen them," says Cuddy. "Many people don't believe seeing women as kind or soft is a stereotype. They're not going to question it because they believe it's a good thing."

Is it a good thing? Kindness and softness are good things in both men and women. But it's not a good thing to hold a candidate to impossible standards. I hear women I know talking about how mean or cold Hillary is, how much they "hate" her. Is she meaner or colder than George Bush or John McCain or Barack Obama or any other male candidate? Hardly. We want her to be momma and the general at the same time. It's the hardest task any candidate has ever faced. But some woman, some time, will have to break through and create a new precedent for female presidential candidates in the future. Most female heads of state around the world have had a family member who preceded them in office. We know that. That much precedent has already been created. Now is the time we can pop that glass ceiling. We're almost there! If not now, how much longer will it be until another opportunity arises?

I believe Hillary's presidency would profoundly change the status of women in this country. I for one am on-fire ready for that. How bout you?

Source:
Drake Bennett. Feb 19 2008. Gender vs. Race: Historic race may show biases of the American mind at work. The Boston Globe.

Key words:: Hillary, racial stereotypes, gender stereotypes, Barack Obama