The recent Paris terrorist attack highlights the discrepancy in the levels of empathy that Western people feel toward other Western people, compared to the empathy they feel toward Middle-Eastern people for example, who suffer such attacks regularly. The question is:How can a person or group of people's empathy be measured?What factors influence this level of empathy? Have any studies been done on this subject? 
What factors influence a person or group of people's empathy toward another group?
empathy