1986年心理學家Robert Sternberg出版了一本名叫"愛的三角理論"用幾何的關係來描述愛。根據他的理論,愛可被劃分為三個組成部分: 1.親密(Intimacy)– which encompasses the feelings of closeness, connectedness, and bondedness 2. 熱情(Passion)– which encompasses the drives that lead to romance, physical attraction, and sexual consummation 3. 決定、承諾(Decision/Commitment)– which encompasses, in the short term, the decision that one loves another, and in the long term, the commitment to maintain that love