Here's my theory:  Some sort of congenital, cognitive condition affecting mature judgment, behavior and ability to control impulse that's closely related to/ the flat head and widely set eyes.

Seen so many mug shots of violent offenders with the same look.  Personally encountered so many with the same look acting out and on the edge.

Why is that?  Something physiological?  Something developmental?  Do these odd looks and the reaction(s) our "right looks" society tends to impose push people over the line (social marginalization)?  COMBINATION of all?