Those displaying on this end of the spectrum may self-report dissociation but no psychological distress per se.

Others have developed less emotional reactivity as an arguably natural reaction to stress. Some of these veterans clearly suffer from a grave disorder commonly known as shell shock and may suffer from recurring nightmares or otherwise experience psychological distress. Veterans of intense combat have been described as having the thousand-yard stare (or thousand-yard gaze). Victims of post-traumatic stress syndrome are often said to display blunted affect. For example, the Japanese are often described as 'unemotional' (even to the point of 'blunted in affect') by Americans, and so the same individual may be considered to display a blunted affect in one culture and be merely 'serious' or 'unemotional' in another. The precise boundary between the generally positive personality trait 'serious' and the generally pathological 'blunted affect' is impossible to describe precisely because it is culture specific and relies on subjective values. Blunted affect is the scientific term describing a lack of emotional reactivity on the part of an individual.

Blunted vs. flat affect