–“Openness/Intellect did not have any significant correlation with the volume of any brain structures.
Conscientiousness was associated with increased volume in the lateral prefrontal cortex, a region involved in planning and the voluntary control of behavior.
Extraversion was associated with increased volume of medial orbitofrontal cortex, a region involved in processing reward information.
Agreeableness was associated with increased volume in regions that process information about the intentions and mental states of other individuals.
Neuroticism was associated with increased volume of brain regions associated with threat, punishment, and negative emotions.”—
DeYoung, C. G.; Hirsh, J. B.; Shane, M. S.; Papademetris, X.; Rajeevan, N.; Gray, J. R. (2010). “Testing Predictions From Personality Neuroscience: Brain Structure and the Big Five”. Psychological Science. 21 (6): 820–828. doi:10.1177/0956797610370159. PMC 3049165 Freely accessible. PMID 20435951.