Welcome to the University of Tulsa's Individual Differences Laboratory. The lab is directed by Allan Harkness, Ph.D. and John McNulty, Ph.D. The laboratory's research focuses on the assessment of individual differences and the relationship between those variations and clinical issues. We use a variety of methods for the collection of individual differences data, including self-report questionnaires, cognitive abilities instruments, laboratory tasks, and the collection of biological samples. While we utilize measures of various models of personality, the laboratory works primarily with the Personality Psychopathology - Five model developed by Drs. Harkness and McNulty and measured with scales on the MMPI-2 and the MMPI-2-RF. The goals of the lab are to identify and assess the stable properties that underlie individual differences traits, to ascertain the relationship between those properties and various biological markers, and to apply that knowledge to clinical diagnosis, assessment, and treatment. We hope you will find this website informative, and we encourage you to contact us if you have any questions about the lab and its projects.