Intergroup theory and attribution theory were applied to 151 voters' perceptions of the causes of electors' intentions to vote for subjects' own preferred party and other parties. An intergroup extension of actor-observer attribution theory predicted that the difference in the explanations should be along the external-internal locus dimension, but in addition it was hypothesized that voters would enhance the differences between themselves and other voters by exaggerating differences in the favourability of the expressed causes. The pattern of internality and evaluation in respondents' accounts of others' intentions only partially supported these predictions. The intergroup differentiation hypothesis was further tested by asking respondents to guess at the accounts of voting that other voters would give. It was predicted that such ascribed attributions would allow greater scope for differentiation, and that subjects would exaggerate the negativity of others' accounts. Results supported this generalized intergroup derogating interpretation for ascribed attributions.