ABSTRACT

At a symptom level the basic evolutionary theory I am proposing suggests that the re-experiencing phenomena of PTSD represent higher order memory and learning experiences. These experiences are associated with hypervigilance (watchfulness) and avoidance behaviours. Simply put, if ancestral individuals have had seriously threatening experiences, their long-term survival might be promoted if their lessons were not forgotten (re-experiencing symptoms); if they remained for an extended period on high alert (overarousal symptoms); if they avoided high-risk locations and activities (avoidance

behaviours); and were quick to use other defences as determined by contextual demands.