Background: The Five Factor Model (FFM) of normal personality provides a compelling framework for investigating personality subtypes in large military populations. The FFM was used to determine whether a sample of clinically referred military aviators exhibited commonly occurring personality clusters.
Methods: The Revised NEO Personality Inventory (NEO-PI-R) was used to evaluate 956 clinically referred U.S. Naval aviators and flight officers on the domains of neuroticism (N), extroversion (E), openness (O), agreeableness (A), and conscientiousness (C). The scores were subjected to model-based cluster analysis and emergent clusters were compared with respect to their scores and clinical outcomes.
Results: A two-cluster model provided the best fit to the data. MANOVA indicated significant differences between the two cluster groups with respect to four of the five factors (N, E, A, and C). The greatest differences were for N and E, with the smaller group (Group 1, N = 291) being significantly more neurotic and less extroverted than Group 2 (N = 665). Cluster membership had more specificity (0.74) than sensitivity (0.59) for predicting adverse clinical outcome, with the probability of an adverse clinical outcome increasing from 0.14 to 0.28 for those in the neurotic and introverted Group 1.
Conclusions: Elevated neuroticism and depressed extraversion were the defining traits of the personality cluster less suited for aviation duty (Group 1). Results support assessment of neuroticism and extroversion during clinical mental health evaluations related to military aviation duty.