Psychologist Harold Bessell in his book "The Love Test", reconciles the opposing forces noted by the above researchers and shows that there are two factors that determine the quality of a relationship. Bessell proposes that people are drawn together by a force he calls "romantic attraction", which is a combination of genetic and cultural factors. This force may be weak or strong and may be felt to different degrees by each of the two love partners. The other factor is "emotional maturity", which is the degree to which a person is capable of providing good treatment in a love relationship. It can thus be said that an immature person is more likely to overestimate love, become disillusioned, and have an affair whereas a mature person is more likely to see the relationship in realistic terms and act constructively to work out problems.