Brain Connectivity: Nature v. Nurture

In December 2013, researchers at the University of Pennsylvania Medical School published a paper detailing cognitive differences between the male and female brain. The research team of psychologists, neurologists, and radiologists utilized diffusion tensor imaging (DTI) to study brain connectivity in 941 individuals ranging from ages 8-22. The study revealed prominent differences in the neural wiring of men and women, which researches dubbed "connectomes" (Verma, 2013).

The differences between male and female brains are almost complementary: researches found greater intra-hemisphere connection in males, while females displayed stronger inter-hemisphere connectivity. The Penn team posits that connectome differences might help to explain why men outperform women in spatial and motor skills, and women excel in memory and social cognition tests. Linear brain wiring in males may explain their apparent advantage in tasks involving coordinated muscle control, such as navigating a map. The strong integration of the logical left brain and intuitive right brain could explain women's multitasking and interdisciplinary approach to problems (Verma, 2013).

Researchers noted that gender differences became more pronounced when individuals matured past age 14. Children under the age of 13 displayed the least amount of cognitive disparity, which supports the writings of Lise Eliot in her book Pink Brain, Blue Brain. Dr. Eliot believes that most gender differences are epigentic in origin, meaning that the environment acts upon our genes to shape how we behave. She writes, "Nature and nurture [are not] distinct warring entities.. but are intricately woven" (Pink Brain, Blue Brain, p. 7).

To be sure, there are sex differences in the brain, as exemplified in Dr. Verma's Penn study. Dr. Eliot also agrees that there are cognitive disparities between males and females, but she thinks that these differences are more than just biological. In her opinion, learning through "practice, role models, and reinforcement" is the most pivotal determinant of gender differences (Pink Brain, Blue Brain, p. 7). Any attempts to explain behavioral differences must consider societal influences. For example, the intra-hemisphere connectome found in males might be a product of a society that raises girls in a way that fosters empathy, interpersonal relationships, and verbal skills. Boys, on the other hand, are treated and taught in a way that produces competitiveness, mathematical prowess, and mechanical ability.

Drawing on studies such as Penn's, Dr. Eliot attempts to explain and trace the origins of cognitive gender differences. She hopes that discovering the intersection between nature and nurture will lead to innovative schooling, parenting, and a societal approach that doesn't constrain individuals on the basis of their gender.

Resources:

http://www.uphs.upenn.edu/news/News_Releases/2013/12/verma/

Eliot, Lise. Pink Brain, Blue Brain: How Small Differences Grow into Troublesome Gaps--and What We Can Do about It.