Why Do Males Have Superior Spatial Ability? Parietal Lobe Structure Clues

A University of Iowa study offers tantalizing clues as to why males show consistent statistical superiority to females in spatial skills. At least part of the explanation may lie in how the brain's parietal lobes are organised.

UI researchers found that a thicker cortex in the parietal lobe in women is associated with poorer mental rotation ability, and in a new structural discovery, that the surface area of the parietal lobe is increased in men, compared to women. Moreover, in men, the greater parietal lobe surface area is directly related to better performance on mental rotation tasks. The study results were published online Nov. 5 by the journal Brain and Cognition.

...The findings underscore the fact that not only is the brain structure different between men and women but also the way the brain performs a task is different, said Peg Nopoulos, M.D., a study co-author and professor of psychiatry and pediatrics at the University of Iowa Carver College of Medicine.

"One possible explanation is that the different brain structures allow for different strategies used by men and women. While men appear able to globally rotate an object in space, women seem to do it piecemeal. The strategy is inefficient but it may be the approach they need to take," said Nopoulos, who also is a psychiatrist with University of Iowa Hospitals and Clinics. _MachinesLikeUs

The statistical superiority of males in spatial skills and advanced mathematical reasoning leads to a higher proportion of males at the rarefied levels of mathematics and math-intensive fields of science, engineering, economics, etc. Such male superiority also leads to the preponderance of males as pilots, race car drivers, and other occupations requiring rapid spatial processing. Politically motivated polemicists often mis-attribute such occupational distributions as due to bias and discrimination.

Reasons for these statistical cerebral distinctions between male and female appear to center around sex hormone exposure in the womb and at other critical developmental periods. Women who are successful in the hard sciences, engineering fields, and other math-intensive vocations often have other male behavioural characteristics -- suggesting male hormonal effect at some point in development.

Race and gender associated brain differences are very politically incorrect. Researchers who study such things tempt the Academic Thought Police. The amazing new tools of study in the neurosciences and psychological sciences are simply too powerful, however, not to use them to explore our rich and diversified human landscape.