Reduced social interaction, loss of social dominance, and inappropriate social interactions are all a result of damage to the rhesus monkey's:

Permanent damage to the amygdala

Amygdala is the integrative center for emotions, emotional behavior, and motivation. T he amygdala is a section of the brain that is responsible for detecting fear and preparing for emergency events. permanent damage of this brain section that deals with emotions has been correlated with a loss of interest in social interaction in the rhesus monkey.