Are girls more prone to play with dolls and cooperate among themselves because they are taught to be so by parents, teachers and social peers, or is it the reverse order? .
Research has shown that gender differences are already apparent from just a few months after birth, when social influence is nominal18. A controversial book "Brain Sex" offers explanations for these very early differences in children18. "These discernible, measurable differences in behavior have been imprinted long before external influences have had a chance to get to work. They reflect a basic difference in the newborn brain which we already know about -- the superior male efficiency in spatial ability, the greater female skill in speech." But now, after many careful controlled studies where environment and social learning were ruled out, scientists learned that there exists a great deal of neuropsychological differences between the brains of males and females6. During the development of the embryo in the womb, circulating hormones have a very important role in the sexual differentiation of the brain8. The presence of androgens in early life produces a "male" brain. In contrast, the female brain is thought to develop via a hormonal default mechanism, in the absence of androgen. However, recent findings have shown that ovarian hormones also play a significant role in sexual differentiation8. .
One of the most convincing evidences for the role of hormones, has been shown by studying girls who were exposed to high levels of testosterone because their pregnant mothers had congenital adrenal hyperplasia. These girls seem to have better spatial awareness than other girls and are more likely to show turbulent and aggressive behavior as kids, very similar to boys8. In the end, research has shown that the way we process information and make decisions is a combination of our inherent biological differences and cultural learning.