This is Life!: Revolutions Around the Cruciform Axis

Boys Will Be Boys--Oh, and Girls Will Be Girls, Too!

From the Zenit News Agency, an article citing research establishing the biological foundation of behavioral differences between the sexes:

Nevertheless, Rhoads argues that "Men and women still have different natures and, generally speaking, different preferences, talents and interests." In support of this affirmation he cites research from a number of sources demonstrating that the behavioral and psychological differences between men and women are in fact real, and not due to social conditioning.

Some sex-difference research has identified the hormonal environment of fetuses in mothers' wombs as a factor explaining differences between male and female behavior. And neuroscientists have found that men have fewer connections between the left and right hemispheres of the brain, with men's brains in general being more compartmentalized than women's.

Male-female divergences are evident from the earliest age, notes Rhoads. Even 1-day-old infants show behavioral differences, with females responding more strongly to the sound of crying. Three-day-old girls maintain eye contact with a silent adult for twice as long as boys. And 4-month-old girls can distinguish photographs of those they know from other people, something boys are generally not capable of doing. Boys, on the other hand, by the age of 5 months are more interested than girls in three-dimensional geometric forms and blinking lights.

Once infants are a year old they can rapidly distinguish between the sexes of their playmates, preferring to associate with those of their own sex. Tests have shown this to be the case even when the newly arrived infants are dressed in the clothes of the opposite sex. Thus, baby girls quickly identify as female another baby, even if it is dressed in masculine clothes.

He goes on to show how these difference continue to manifest themselves into adulthood.