Infant Behavior Correlates With Brain Differences as Adults

Infant Behavior Correlates With Brain Differences as AdultsJoan Arehart-Treichel The old saying that stubborn people are “thickheaded” may have some basis in fact. Individuals who are nonfearful, bold, uninhibited—and perhaps stubborn—may have a thick orbitofrontal cortex. Why are certain people fearful, timid, and inhibited, whereas others are nonfearful, bold, and uninhibited? Certainly genes play a role, but brain architecture may as well, a new study suggests. It has found differences in brain thickness between adults who had been extremely fearful, timid, and inhibited as infants and adults who had not been. The lead investigator was Carl Schwartz, M.D., an assistant professor of psychiatry at Harvard Medical School. The results were published in the January Archives of General Psychiatry. Both the ventromedial prefrontal cortex and the orbitofrontal cortex are known to have rich neural connections with the amygdala, the brain's anxiety center, and to play pivotal roles in emotional regulation and behavioral inhibition. Schwartz and his colleagues wanted to find out whether there were any differences in these two brain regions in fearful and nonfearful people. They focused on 76 18-year-olds who had been enrolled as infants in a longitudinal study of child development. At age 4 months, 34 of them were found to be extremely fearful, timid, and inhibited in temperament, whereas the remaining 42 were found to be the opposite. As the subjects matured, they tended to react to unfamiliar people, objects, and situations as they had in infancy. Schwartz and his coworkers used structural MRI scans to measure...