The study of sex differences over the time

St. Thomas Aquinas

Summa Theologica

“As regards the individual nature, woman is defective and misbegotten, for the active force in the male seed tends to the production of a perfect likeness in the masculine sex; while the producti on of woman comes from defect in the active force or from some material indisposition, or even from some external influence, such as that of a south wind, which is moist…”

Dr. Edward Clarke

In 1873, Harvard professor Dr. Edward Clarke wrote a best-selling book in which he asserted that women should not be allowed to attend college. If young women studied too much, he asserted, they would divert blood away from the uterus to the brain, rendering themselves “irritable and infertile.”

Paul Julius Möbius

German neurologist, Paul Julius Möbius, carefully measured the volume of the skulls by pouring sand into skulls of men and women of different ages and weights. Using this method, he found that the cranial capacity of the skull in a man averaged about 8% more than in the skull of a woman the same age and height. He concluded that women are “physiologically weak-minded.”

NeuroImage

Sexual dimorphism of brain developmental trajectories during childhood and adolescence

“More dead space in the male brain. There are large holes in the brain, called the lateral ventricles. The ventricles store cerebrospinal fluid, the water which cushions the brain against injury. These holes in the brain are about 20% larger in men than in women. This difference can’t be explained by height; even in 10-year-old boys, who are the same height (on average) as 10-year-old girls, these holes in the brain are still about 20% bigger.”

UCLA Study

General intelligence equal between sexes

Women have proportionately more gray matter. The cerebral cortex is significantly thicker in women than in men. (The cerebral cortex is where most of our complex thinking takes place.) When you adjust for size differences between women and men, the differences become even more dramatic, with the cortex being thicker in many areas in women’s brains compared with men. The red areas in the figure at right shows the areas of the brain where the cortex is thicker in women. There is no region of the brain where the cortex is thicker in men than in women.