By studying the injuries and aptitudes of Vietnam War veterans who suffered penetrating head wounds during the war, researchers have found that brain regions that contribute to optimal social functioning are also vital to general intelligence and emotional intelligence.
This finding, reported in the journal Brain, bolsters the view that general intelligence emerges from the emotional and social context of one’s life.
“We are trying to understand the nature of general intelligence and to what extent our intellectual abilities are grounded in social cognitive abilities,” said Aron Barbey, a University of Illinois professor of neuroscience, psychology, and speech and hearing science.
Barbey, an affiliate of the Beckman Institute and he Institute for Genomic Biology at the University of Illinois, led the new study with an international team of collaborators.
The study involved 144 Vietnam veterans injured by shrapnel or bullets that penetrated the skull, damaging distinct brain tissues while leaving neighboring tissues intact. Using CT scans, the scientists painstakingly mapped the affected brain regions of each participant, then pooled the data to build a collective map of the brain.
The researchers used a battery of carefully designed tests to assess participants’ intellectual, emotional and social capabilities. They then looked for damage in specific brain regions tied to deficits in the participants’ ability to navigate intellectual, emotional or social realms. Social problem solving in this analysis primarily involved conflict resolution with friends, family and peers at work.
As in their earlier studies of general intelligence and emotional intelligence, the researchers found that regions of the frontal cortex (at the front of the brain), the parietal cortex (further back near the top of the head) and the temporal lobes (on the sides of the head behind the ears) are all implicated in social problem solving. The regions that contributed to social functioning in the parietal and temporal lobes were located only in the brain’s left hemisphere, while both left and right frontal lobes were involved.