When under stress our ability to rationalize and reason is compromised due to the environmental priorities that require we be stronger and faster than smarter or more socially acceptable. When we are in a rapid and fast changing environment our perception becomes our primary information receiver and can also influence how we interpret information is it friend or foe and our categories at the cognitive level become simplified and expedient. No fluff, just hard facts with lots of inaccuracies if we were to try to reason or friend or befriend with. Our deeper neural structures are about survival of the individual and makes us a bit intense of aspect and less apt to look friendly in the face of stress, anxiety or danger.