A triangle is a three-person relationship system. It is considered the building block or “molecule” of larger emotional systems because a triangle is the smallest stable relationship system. A two-person system is unstable because it tolerates little tension before involving a third person. A triangle can contain much more tension without involving another person because the tension can shift around three relationships. If the tension is too high for one triangle to contain, it spreads to a series of “interlocking” triangles. Spreading the tension can stabilize a system, but nothing gets resolved.

People’s actions in a triangle reflect their efforts to assure their emotional attachments to important others, their reactions to too much intensity in the attachments, and their taking sides in others’ conflicts. Paradoxically, a triangle is more stable than a dyad, but a triangle creates an odd man out, which is a very difficult position for individuals to tolerate. Anxiety generated by anticipating being or by being the odd man out is a potent force in triangles.

The patterns in a triangle change with increasing tension. In calm periods, two people are comfortably close “insiders” and the third person is an uncomfortable “outsider.” The insiders actively exclude the outsider, and the outsider works to get closer to one of them. Someone is always uncomfortable in a triangle and pushing for change. The insiders solidify their bond by choosing each other in preference to the less desirable outsider. When someone chooses another person over oneself, it arouses particularly intense feelings of rejection.

If mild to moderate tension develops between the insiders, the most uncomfortable one will move closer to the outsider. One of the original insiders now becomes the new outsider and the original outsider is now an insider. The new outsider will make predictable moves to restore closeness with one of the insiders. At moderate tension levels, triangles usually have one side in conflict and two harmonious sides. The conflict is not inherent in the relationship in which it exists, but reflects the overall functioning of the triangle.

At a high level of tension, the outside position becomes the most desirable. If severe conflict erupts between the insiders, one insider opts for the outside position by getting the current outsider fighting with the other insider. If the maneuvering insider is successful, he gains the more comfortable position of watching the other two people fight. When the tension and conflict subside, the outsider will try to regain an inside position.

Triangles contribute significantly to the development of clinical problems. For example, getting pushed from an inside to an outside position can trigger a depression or perhaps even a physical illness, or two parents intensely focusing on what is wrong with a child can trigger serious rebellion in the child.


Michael and Martha were extremely happy during the first two years of their marriage. Michael liked making major decisions, and Martha felt comforted by Michael’s “strength.” After some difficulty getting pregnant, Martha conceived during the third year of the marriage, but it was a difficult pregnancy. She was quite nauseous during the first trimester and developed blood pressure and weight gain problems as the pregnancy progressed. She talked frequently to Michael of her insecurities about being a mother. Michael was patient and reassuring, but also began to feel critical of Martha for being “childlike.”

Analysis: The pregnancy places more pressure on Martha and on the marital relationship. Michael is outwardly supportive of Martha, but is reactive to hearing about her anxieties. He views her as having a problem.

A female infant was born after a long labor. They named her Amy. Martha was exhausted and not ready to leave the hospital when her doctor discharged her. Over the next few months, she felt increasingly overwhelmed and extremely anxious about the well-being of the young baby. She looked to Michael for support, but he was getting home from the office later and Martha felt he was critical of her coping problems and that he dismissed her worries about the child. There was much less time together for just Michael and Martha and, when there was time, Michael ruminated about work problems. Martha became increasingly preoccupied with making sure her growing child did not develop the insecurities she had. She tried to do this by being as attentive as she could to Amy and consistently reinforcing her accomplishments. It was easier for Martha to focus on Amy than it was for her to talk with Michael. She reacted intensely to his real and imagined criticisms of her. Michael and Martha spent more and more of their time together discussing Amy rather than talking about their marriage.

Analysis: Martha is the most uncomfortable with the increased tension in the marriage. The growing emotional distance in the marriage is balanced by Martha getting overly involved with Amy and Michael getting overly involved with his work. Michael is in the outside position in the parental triangles and Martha and Amy are in the inside positions.

As Amy grew, she made increasing demands on her mother’s time. Martha felt she could not give Amy enough time, that Amy would never be satisfied. Michael agreed with Martha that Amy was too selfish and resented Amy’s temper tantrums when she did not get her way. However, if Michael got too critical of Amy, Martha would defend Amy, telling Michael he was exaggerating. Yet, whenever tensions developed between Martha and Amy, Martha would press Michael to spend more time with Amy to reassure her that she was loved. He gave into Martha’s pleas, but inwardly felt that they were following a policy of appeasement that was making Amy more demanding. Michael felt that if Martha had his maturity, Amy would be less of a problem, but, despite this attitude, Michael usually followed Martha’s lead in relationship to Amy.

Analysis: When tension builds between Martha and Amy, Michael sides with Martha by agreeing that Amy is the problem. The conflictual side of the triangle then shifts from between Martha and Amy to between Michael and Amy. If the conflict gets too intense between Michael and Amy, Martha sides with Amy, the conflict shifts into the marriage, and Amy gains the more comfortable outside position.