Paul T. Costa, Jr. was born in New Hampshire in 1942. He received his BA in Psychology from Clark University, and his MA and PhD in Human Development from the University of Chicago. His early work was concerned with aging, and the effects of age on cognition and personality. He has become widely known for his more general work on the structure of human personality. He has developed, with McCrae the influential 'five-factor' model of personality differences.
Costa is currently chief of the US National Institutes of Health's Laboratory of Personality and Cognition