Alternative Research

Reward/Need theory
In a laboratory experiment, Lehr and Geher (2006) studied participants of both sexes to test the importance of reciprocal liking. Knowing that someone likes you is particularly rewarding and so is more likely to result in mutual liking. Participants were given a description of a stranger, with varying degrees of similarity of the strangers attitudes to the participant's. In each description was a statement that the stranger either liked or did not like the participant. The dependent variables included measure of liking for the stranger. Researchers found significant effects for attitude similarity and liking.
Cate et al (1982) asked 337 individuals to assess their current relationships in terms of reward level and satisfaction. Results showed that reward level was superior to all other factors in determining relationship satisfaction. However, a basic problem with this theory is that it only explores the receiving of rewards, whereas Hays (1985) found that we gain satisfaction from giving as well as receiving.
Similarity theory
Research has consistently demonstrated that people are more likely to be attracted to others who have similar personality traits than they are to those who have dissimilar or complementary traits (Berscheid and Reis 1998). This is not always the case, but similarity is more often the rule in long term relationships. Caspi and Herbener (1990) found that married couples with similar personalities tend to