Similarity can occur in terms of social characteristics, personal characteristics, and attitudes and values. Similarity is important because there needs to be something in common that brings individuals together and serves as a basis for interaction. How strong the similarity needs to be depends on the kind of social relationship, from strangers with little in common, to friends with some things in common, to lovers ideally with much in common. However, perceived similarity is often more important than actual similarity (Montoya, Horton, & Kirchner, 2008).