Brent W. Roberts   On this episode of Unsupervised Learning, Razib discusses personality with Brent Roberts, professor of psychology at the University of Illinois. Roberts explains what personality actually is as a psychological construct, and how it differs from personality traits, like extraversion. Razib and Roberts also address the Big Five Personality system, and how it relates to the Myers-Briggs framework. Roberts elucidates what the Big Five’s extraversion, openness, conscientiousness, neuroticism and disagreeability actually mean, and how they correspond to Myers-Briggs dichotomies of extraversion/introversion, sensing/intuitive, thinking/feeling and judging/perceiving. Though Myers-Briggs may have some shortcomings, for example collapsing continuities in discrete categories, Roberts maintains that it still retains some utility, and is not as unscientific as many researchers assert. Razib then asks about personality’s relationship to behavior genetics. What is the heritability of personality’s subcomponents? How do they interrelate? And what might the evolutionary context of personality variation be? Roberts also addresses the idea that personality traits can change over one’s lifetime, and are unstable from test to test. Razib also wonders how different traits, like agreeability, correlate with life outcomes in income and happiness. Finally, they discuss the nature of psychopaths and sociopaths, and how they relate to the Big Five categories.