Evolutionistx thinks so. She started pondering this in view of the fact that 25% of women in the U.S. are on medications for depression or anxiety. Why so many drug users? A quote:
People seem to do best, emotionally, when they have the support of their kin, some degree of ethnic or national pride, economic and physical security, attend religious services, and avoid crowded cities. (Here I am, an atheist, recommending church for people.) The knowledge you are at peace with your tribe and your tribe has your back seems almost entirely absent from most people’s modern lives; instead, people are increasingly pushed into environments where they have no tribe and most people they encounter in daily life have no connection to them. Indeed, tribalism and city living don’t seem to get along very well.
Over the course of the last 200,000 years, tribes were probably no more than 150 people.