This paper briefly and informally surveys different theoretical models of relative concerns and their relation to inequality. Models of inequity aversion in common use in experimental economics imply a negative relation between inequality and happiness. In contrast, empirical studies on...

The human tendency to cooperate with nonkin even in short-run relationships remains a puzzle. Recently it has been hypothesized that altruism may be a byproduct of “mentalizing”, the process of understanding and predicting the mental states of others. Another idea is based on sexual...