Personality and Endocrine Activation in Military Stress Situations

Abstract

The objective of this study was to identify personality traits that predict coping in stressful military settings and to examine if personality clusters found in U.S. pilot populations could be replicated in Norwegian Army (n = 35) and Air Force (n = 44) cadets. All participants completed the Personality Characteristic Inventory (PCI), and stable personality profiles corresponding to those found in U.S. pilot populations were identified. The Air Force cadets performed two stressful exercises, and serum levels of cortisol and testosterone were measured before and after the exercises. Afterwards, the cadets evaluated their own physical performance. Thirty-eight of the 44 Air Force cadets could be classified into the PCI personality clusters that related differentially to the physiological stress response. Cadets characterized by strong instrumental and expressive traits (the “right stuff”) had lower cortisol values and larger testosterone–cortisol ratios than others, which is interpreted as indicative of superior coping. There were no associations between personality and self-reported physical performance.