Combat adaptations of Vietnam veterans without posttraumatic stress disorders.

Ten veterans who did not develop posttraumatic stress after intense combat in Vietnam were studied to explain what had protected them. The authors found a highly consistent adaptation to combat: During combat each of these veterans had exhibited calmness under pressure, intellectual control, acceptance of fear, and a lack of excessively violent or guilt-arousing behavior. The authors believe that these traits may be part of an adaptation uniquely suitable for preserving emotional stability in an unstructured, unstable context.