Empathy and humanity.

This has been called the Age of Empathy; empathy is seen as the glue that holds society together, the capacity without which humans would not have evolved. It is the ability to accurately perceive others internal states and to have affective responses to them. Empathy is most likely to emerge with those with whom we are familiar, those that are an 'us'. Universally, humans divide 'us' and 'them.' Those in the out-group are treated with disdain, and sometimes with lethal actions. In human history and psychology, trends often move in opposite directions. Empathy has a limited domain, and is accompanied by hostility to 'outsiders'.