Sternberg Triangle

                   Intimacy
                         /\
                        /  \
                       /    \
                      /      \
                     /        \
                    /          \
                   /            \
                  /              \
                 /                \
                /                  \
Passion --------------- Decision/Commitment

The Sternberg Triangle (above) was created by Yale professor Robert Sternberg in his 1988 book with Michael Barnes called The Psychology of Love. The triangle holds that three things interact to promote or negate love: intimacy, passion, and decision/commitment.

• Intimacy - involves the nature of human interaction and is not confined to sexual contact. In Sternberg's view intimacy includes such attributes as: dependency (on each other), mutual understanding and mutual happiness.
• Passion - is the sexual/physical component of love. Even though passion is related to intimacy, they are not interchangeable terms. Sternberg feels that intimacy (as defined above) stimulates passion.
• Decision/Commitment - is made up of two phases: short term and long term. Short term is simply the decision to love someone. Long term is the decision to invest in that love emotional (and often financial) resources.

Sources:
Sternberg, Robert J. and Barnes, Michael L. (Eds.). The Psychology of Love. Yale University Press: New Haven, CT 1988.

Shriver, Sharon P et al. (Eds). Dimensions of Human Sexuality (6th Edition). McGraw Hill: New York 2000.