Psychology depicts love as a cognitive and social phenomenon. PsychologistRobert Sternberg formulated a triangular theory of love and argued that love has three different components: Intimacy, Commitment, and Passion. Intimacy is a form by which two people can share secrets and various details of their personal lives. Intimacy is usually shown in friendships and romantic love affairs. Commitment, on the other hand, is the expectation that the relationship is going to last forever. The last and most common form of love is sexual attraction and passion. Passionate love is shown in infatuation as well as romantic love. This led researchers such as Yela to further refine the model by separating Passion into two independents components: Erotic Passion and Romantic Passion.
Following developments in electrical theories, such as Coulomb's law, which showed that positive and negative charges attract, analogs in human life were developed, such as "opposites attract". Over the last century, research on the nature of human mating has generally found this not to be true when it comes to character and personality; people tend to like people like themselves. However, in a few unusual and specific domains, such as immune systems, it seems that humans prefer other who are unlike themselves (e.g. with an orthagonal immune system), since this will lead to a baby which has the best of both worlds. In recent years, various human bonding theories have been developed described in terms of attachments, ties, bonds, and or affinities.
Some Western authorities disaggregate into two main components, the altruistic and the narcissistic. This view is represented in the works of Scott Peck, whose works in the field of applied psychology explored the definitions of love and evil. Peck maintains that love is a combination of the "concern for the spiritual growth of another", and simple narcissism. In combination, love is an activity, not simply a feeling.