We introduce a theoretical framework in which to study interdependent preferences, where the outcome of others affects the welfare of the decision maker. The dependence may take place in two conceptually different ways, which depend on how the decision maker evaluates what the others have. In the first he values his outcome and that of others on the basis of his own utility. In the second, he ranks outcomes according to a social value function. We give different axiomatic foundations to these two different, though complementary, views of the nature of the interdependence. We characterize preferences according to the relative importance assigned to social gains and losses, that is, pride and envy.