In the following excerpt, Murray refutes Woll-stonecraft's claim that "the mind has no sex." Building his case on biological determinism, he asserts that males think more, especially about concrete problems; while females exhibit a more "empathetic" brain type.

Two centuries ago, protofeminist Mary Wollstonecraft wrote a treatise entitled "A Vindication of the Rights of Woman" in which she theorized that men and women are essentially the same. The roles they play, she suggested, are merely social constructs. The buzz phrase since then has been that "the mind has no sex."

But there is growing scientific evidence that the mind does have a sex, and that other unexpected components of the body have a sex as well. There are significant differences between men and women in their brains and genes as well.

There are two strands to this data: animal research and human research. Among animals, it seems...