Propinquity refers to a person’s familiarity with another person, which can be caused by spending time together, living near each other, thinking about the other, or anticipating interaction with the other. Similarity refers to the similarity of people’s beliefs and, to a lesser extent, similarity of personality traits and ways of thinking. Desirable characteristics refer to an outer physical appearance that is deemed desirable. A possible union that meets common social norms, as well as acceptance of the potential union within one’s social network, can all contribute to people falling in love. In contrast, a partnership that does not meet common social norms or is not accepted by one’s social network might lead to people falling out of love. Needs are being met. If a person can meet the wants for companionship, love, sex, or mating, the other person is more likely to fall in love with him or her.
