Although it is a very important variable, finding someone physically attractive is of course often only the first stage in developing a close relationship with another person. If we find someone attractive, we may want to pursue the relationship. And if we are lucky, that person will also find us attractive and be interested in the possibility of developing a closer relationship. At this point, we will begin to communicate, sharing our values, beliefs, and interests, and begin to determine whether we are compatible in a way that leads to increased liking.
Relationships are more likely to develop and be maintained to the extent that the partners share external, demographic characteristics, and internal ones like values and beliefs. Research across many cultures has found that people tend to like and associate with others who share their age, education, race, religion, level of intelligence, and socioeconomic status (Watson et al., 2004). It has even been found that taller people tend to like other tall people, that happy people tend to like other happy people, and that people particularly enjoy being with others who have the same birthday and a similar sense of humor (Jones, Pelham, Carvallo, & Mirenberg, 2004; Pinel, Long, Landau, Alexander, & Pyszczynski, 2006). One classic study (Newcomb, 1961) arranged for male undergraduates, all strangers, to live together in a house while they were going to school. The men whose attitudes were similar during the first week ended up being friends, whereas those who did not initially share attitudes were significantly less likely to become friends.