Dissimilarity and similarity between attitudes of the participants and a stranger were manipulated across two sets of issues to test the attraction, repulsion and similarity-dissimilarity asymmetry hypotheses. Participants (N = 192) judged social (liking, enjoyment of company) and intellectual (intelligence, general knowledge) attractiveness of the stranger. The similarity in the first set of attitudes x similarity in the second set of attitudes effect emerged in social attraction, but not in intellectual attraction. Stated simply, dissimilarity had a greater weight than similarity in social attraction, but equal weight in intellectual attraction. These results support the similarity-dissimilarity asymmetry hypothesis that predicts dissimilarity-repulsion to be stronger than similarity-attraction. However, they reject (1) the attraction hypothesis that dissimilarity and similarity produce equal and opposite effects on social attraction; and (2) the repulsion hypothesis that only dissimilar attitudes affect social attraction by leading to repulsion. An equal weighting of dissimilarity and similarity in intellectual attraction further suggested that the similarity-dissimilarity asymmetry on social attraction is reflective of a stronger avoidance response in the Darwinian sense.