We study the effects of social interactions on individual’s other-regarding preferences. Using a modified dictator game, we compare five models of other-regarding preferences and, using our preferred specification, we examine whether a change in an individual’s preferences is observed after the subjects have interacted with regard to the game face-to-face in a small group. We find that these interactions do indeed change individual’s preferences and that these effects are highly heterogeneous. In most groups preferences become more homogenous after social interactions as might be expected, but we also find that preferences often converge towards those of a key individual whose preferences are both extreme and also unchanging. These key individuals tend to have strong preference for own payoff and are are more likely to be male. These effects are more prevalent amongst student subjects compared to non-students.