Three distinct theoretical explanations for the effect of attire on aiding behavior were examined in a study. The reinforcing value of attire itself predicted that well-dressed persons would always receive more assistance than poorly dressed persons. The reinforcing value of perceived similarity predicted that similar persons would receive more assistance than dissimilar persons. Balance theory predicted that dissimilar persons would receive more assistance than similar persons. Seventeen female college students who were well-dressed or poorly dressed approached both males and females in an airport or bus station asking for a dime to complete a telephone call. Well-dressed students received more money at the airport; poorly dressed students received more money at the bus station. The results were interpreted as support for the similarity hypothesis. (Author)