Nature/Nurture

The Lawrence Summers debacle has spurred the expected flood of discussions about the differences between men and women.

This is one of my favorite diversions: what is biological and what is social?

One New York Times article "Gray Matter and Sexes: A Gray Area Scientifically" By Natalie Angier and Kenneth Chang, Published: January 24, 2005, points out that while differences exist (obviously) it is unclear as to how, and to what extent such differences are important to modern life.

The authors go on to cite some of the evidence:
>Women's brains are 10% smaller
>Women's brains have more gray matter than men's brains
>There is little difference in cognitive development between the ages of 5 months and 7 years
>There is evidence that in many countries men to better than women on the math portion of the SAT test (30-35 points on average: a significant but relatively small difference)
>In Japan, women perform the same as men at math
>In Iceland, women outperform men at math

>In all countries, women talk about math and their abilities/interests in a more negative way than do men

Other evidence cites the importance of culture:

Yu Xie, a sociologist at the University of Michigan said he wished there was less emphasis on biological explanations for success or failure, and more on effort and hard work. Among Asians, he said, people rarely talk about having a gift or a knack or a gene for math or anything else. If a student comes home with a poor grade in math, he said, teh parents push the child to work harder. "There is good survey data showing that this disbelief in innate ability, and teh conviction that math achievement can be improved through practice," Dr. Xie said, "is a tremendous cultural asset in Asian society adn among Asian-Americans."

In another New York Times article, "Different but (Probably) Equal" Olivia Judson (evolutionary biologist and author of a fascinating book Dr. Tatiana's Sex Advice to All Creation: The Definitive Guide to the Evolutionary Biology of Sex) states her hypothesis:

Males and females are typically indistinguishable on the basis of their behaviors and intellectual abilities.

She goes on to say that this is certainly not true for many (most?) species. She gives three examples, the most interesting of which is the green spoon worms.

This animal, which lives on the sea floor, has one of the largest known size differences between male and female: the male is 200,000 times smaller. He spends his whole life in her reproductive tract, fertilizing egges by regurgitating sperm through his mouth. He's so different from his mate that when he was first discrovered by science, he was not recognized as being a green spoon worm; instead, he was thought to be a parasite.

The hypothesis is obviously not true for humans either. I am currently at a coffee shop and, get this, I can tell which humans are men and which are women just by looking at them!

But, as Judson points out, although its true that men and women are different, its probably not fashionable to point it out what with discrimination and all of that.

She goes on to postulate about why there are sex differences at all. She claims that bigger differences between sexes are observed when there are major differences between the males and the females in terms of survival. The implications for humans is that it is not ludicrous to strive for a more equal society because we're not that different.

With regard to the SAT math test, 30-35 points is just a couple of questions. So, to (ironically) paraphrase Deirdre N. McCloskey*, size matters in love and statistics. Yes, men do better on the math score of the SAT and it is a statistically significant difference. But is that difference big? No.

*Deidre N. McClosky, formerly the famed Harvard economist, Donald NcClosky, is famous for, among other things, publicly transitioning from a man to a woman during the mid-1990s. Her autobiography Crossing is an interesting read.