We specify and estimate an econometric model which separately identifies distributional preferences and the effects of perceived intentions on responder behavior in the ultimatum game. We allow the effects of perceived intentions to depend, among other things, on the subjective probabilities responders attach to the possible offers. We estimate the model on a large representative sample from the Dutch population. We find that the relative importance of distributional preferences and perceived intentions depends significantly on the socioeconomic characteristics of responders. Strong inequity aversion to the other player's disadvantage is found for lower educated and older respondents. Responders tend to punish unfavorable offers more if they expect that fair proposals will occur with higher probability.