An individual's personality appears to be linked partly to the size of different parts of the brain, new research from the University of Minnesota reveals.
The observation is based on correlations made between personality questionnaires completed by 116 men and women and brain imaging scans that measured the size of various brain regions.
A team led by Colin DeYoung of the University of Minnesota found that four out of the five principle personality "factors" as typically characterised by psychologists - conscientiousness, extraversion, neuroticism, agreeableness and openness/intellect - were associated with differences in regional brain mass. DeYoung and his colleagues report their findings online in Psychological Science.
Extroverts, for example, are generally more involved in the quest for rewards.
What the findings mean
Using a computer program to compare the relative sizes of different structures in each brain image, the authors noted that participants who described themselves as extroverted had a significantly larger medial orbitofrontol cortex - a part of the brain active in considering rewards. Perhaps not surprisingly, those self-described as conscientious had a bigger lateral prefrontal cortex - a section of the brain involved in planning and controlling behaviour.
Being neurotic and agreeable, respectively, also corresponded to differences in regional brain mass, the authors noted.
In fact, the only personality factor seemingly not associated with the size of a specific brain part was openness/intellect, the research team noted.
"This starts to indicate that we can actually find the biological systems that are responsible for these patterns of complex behaviour and experience that make people individuals," DeYoung said in a news release.
Nevertheless, DeYoung noted that the personality is not an immutable force, given that the brain grows and changes in reaction to experience. Such changes in the brain can ultimately change personality. - (HealthDay News, June 2010)