An individual's personality traits such as being moody or empathic is associated with the shape of his or her brain, findings of a new study revealed
Structural Brain Differences And Different Personality Types
In a new study published in the journal Social Cognitive and Affective Neuroscience on Jan. 24, researchers found that the structure of the brain offers clues about the way a person behaves and may even indicate that person's risk of developing mental health disorders.
Luca Passamonti of the University of Cambridge and colleagues looked at the brain scans of more than 500 people between 22 and 36 years old to study the differences in the brain's cortex, neural tissues linked to thought and action.
By looking at the combination of surface area, thickness, and the number of folds in the cortex of different people, the researchers found correlation between structural brain differences and main personality types.
Neuroticism, or how moody an individual is, is associated with a smaller area, foldings in some regions of the brain, and thicker cortex. Neuroticism is a trait behind mental illnesses such as anxiety disorders.
Openness, which reflects creativity and curiosity, is linked to thinner cortex and greater area and folding, while agreeableness is linked to a thinner prefrontal cortex, which is involved in tasks that include processing empathy and other social skills.
Cortical Stretching
The differences in brain structure can be attributed to cortical stretching, the developmental process that shapes the brain in a manner that maximizes the area and amount of folding while minimizing thickness.
The researchers explained that the deep folds in the brain are the evolutionary equivalent of fitting a large supercomputer into a relatively small container, which, in this case, is the human skull.
"Evolution has shaped our brain anatomy in a way that maximizes its area and folding at the expense of reduced thickness of the cortex," Passamonti said.
"It's like stretching and folding a rubber sheet — this increases the surface area, but at the same time, the sheet itself becomes thinner. We refer to this as the 'cortical stretching hypothesis.'"
Cortical stretching hints that the brain's cortex becomes thinner while its area and folding increase as people get older. It also explains observations why people tend to be more neurotic at a younger age. As people get older, they learn how to deal with their emotions and become more agreeable and conscientious.
Mental Illness Risks
The difference in brain structure and personality also suggests that brain changes can be more pronounced in people suffering from mental illness.
"Cortical thickness and surface area/folding were inversely related each others as a function of different five-factor model traits (neuroticism, extraversion and consciousness vs openness), which may reflect brain maturational effects that predispose or protect against psychiatric disorders," the researchers wrote in their study.
The link between the brain structure and basic personality traits can help in improving understanding of mental disorders. It may eventually give researchers the chance to identify individuals who have increased risk for developing mental illness, which could mean prompt intervention.
