A great deal of psychological research supports the folk wisdom that birds of a feather flock ...

Answer: One way we perceive similarity is through shared attitudes and values. We tend to find those who hold similar attitudes and values more attractive than dissimilar others because people who are similar to us provide us with very important validation of our own attitudes, characteristics, and beliefs. Second, we tend to draw negative inferences about people who disagree with us, perhaps because we associate those people's attitudes or beliefs with the characteristics of people we have found in the past to be unpleasant, stupid, weak, or thoughtless. Finally, we expect that people with similar values will like us in return, which makes us likely to attempt to initiate these relationships.