There’s Only One Brain!

Now of course I have to bring in the other element—not nurture, but the biology of how little boys and girls are wired neurologically and hormonally. Unlike little boys, little girls have an initial growth spurt in the left hemisphere of the brain. As a result of this difference in neurological development, they tend to become more fluent and develop a greater repertoire of speech and language skills than boys. Little boys take about four years to catch up with this growth spurt. In the meantime, some serious environmental stimulation has taken place, and little girls get more parental verbal attention because they are more responsive, due to the advanced growth of their neuroanatomy.
In this case, the behavior of parents corresponds to real physiological characteristics. This is not true in the case of parents conditioning their sons to be more mechanically and mathematically inclined. The right hemispheres of boys’ brains do not grow more rapidly than those of little girls; the difference is purely environmental. In fact, I, along with many other specialists in the field, believe that if little girls were equally encouraged in mechanical and cognitive abilities, we would observe little or no differences between the sexes in this area.