As some of you may know, I am a dedicated reader of Language Log, the blog where a bunch of linguists hold forth on a variety of topics, sometimes only tangentially related to linguistics. Their posts ridiculing ignorant peeve-rants about the degeneration of English are hugely enjoyable; but another frequent theme is bad science writing and modern forms of innumeracy.
However, in this post Mark Liberman singles out an article in the New York Times Magazine for praise for finding a way to explain how “small but statistically reliable differences in group distributions” should not be seen as “essential properties of the groups themselves.”
The article profiles a school that is changing its educational policies based on hack theories about male and female brains:
On an unseasonably cold day last November in Foley, Ala., Colby Royster and Michael Peterson, two students in William Bender’s fourth-grade public-school class, informed me that the class corn snake could eat a rat faster than the class boa constrictor. Bender teaches 26 fourth graders, all boys. Down the hall and around the corner, Michelle Gay teaches 26 fourth-grade girls. The boys like being on their own, they say, because girls don’t appreciate their jokes and think boys are too messy, and are also scared of snakes. The walls of the boys’ classroom are painted blue, the light bulbs emit a cool white light and the thermostat is set to 69 degrees. In the girls’ room, by contrast, the walls are yellow, the light bulbs emit a warm yellow light and the temperature is kept six degrees warmer, as per the instructions of Leonard Sax, a family physician turned author and advocate who this May will quit his medical practice to devote himself full time to promoting single-sex public education.
Are there differences between male and female brains? Research findings suggest there are some. Does any brain research yet suggest that differential single-sex education is superior to co-ed classrooms? Hardly.
Scans of boys’ and girls’ brains over time also show they develop differently. Analyzing data from the largest pediatric neuro-imaging study to date — 829 scans from 387 subjects ages 3 to 27 — researchers from the National Institute of Mental Health found that total cerebral volume peaks at 10.5 years in girls, four years earlier than in boys. Cortical and subcortical gray-matter trajectories peak one to two years earlier in girls as well. This may sound very significant, but researchers claim it means nothing for educators, or at least nothing yet. “Differences in brain size between males and females should not be interpreted as implying any sort of functional advantage or disadvantage,” the N.I.M.H. paper concludes. Not one to be deterred, Sax invited Jay Giedd, chief of brain imaging at the Child Psychiatry Branch at N.I.M.H., to give the keynote address at his N.A.S.S.P.E. conference in 2007. Giedd spoke for 90 minutes, but made no comments on schooling at all.
One reason for this, Giedd says, is that when it comes to education, gender is a pretty crude tool for sorting minds. Giedd puts the research on brain differences in perspective by using the analogy of height. “On both the brain imaging and the psychological testing, the biggest differences we see between boys and girls are about one standard deviation. Height differences between boys and girls are two standard deviations.” Giedd suggests a thought experiment: Imagine trying to assign a population of students to the boys’ and girls’ locker rooms based solely on height. As boys tend to be taller than girls, one would assign the tallest 50 percent of the students to the boys’ locker room and the shortest 50 percent of the students to the girls’ locker room. What would happen? While you’d end up with a better-than-random sort, the results would be abysmal, with unacceptably large percentages of students in the wrong place.
Of course, in elementary school the height/locker room assignment would be almost completely random, and in middle school, there might be more girls than boys in in boys locker room, and vice-versa. A better analogy would be an adult fitness club that made locker room assignments based on height. How many people reading this might find themselves in the “wrong” locker room on this basis? And remember that the correlation between gender and height is stronger than the correlation between gender and brain development rates, (and also remember that there’s no evidence that the differential development rate is related to learning in any way.)
While being assigned to the wrong locker room would no doubt be traumatic, think about the harm that is caused by teaching girls that it is unfeminine to to like reptiles, or depriving boys of opportunities to learn how to work together cooperatively.
It’s time to chuck the “evidence-free rubbish” out of our schools.