Everyone knows it’s wrong to cheat when they’re in a in a relationship.

Is your relationship at risk because of too much emotional distance at home?
Yet despite the predictable terrible consequences, infidelity has always been, and probably always will be, part of the relationship landscape. The question is, why? In my last blog post I exposed some common myths about affairs. Now it’s time for the truth.
Truth #1: There is undoubtedly an evolutionary advantage to having offspring with multiple partners. Primates and other mammals often live in “harems” of multiple females led by one dominant male. Males compete for control of the harem. The dominant male gets to mate with all the available females while the lesser ranking males are lucky if they get to sneak off and have an “affair” with a rebellious female (yes, females have affairs too). Otherwise, low ranking males don’t reproduce at all. Of course, even if humans have this tendency in our DNA, we don’t have to act on it.
Truth #2: Affairs are born out of the relationship process. The beginning of the relationship is the time when things are easiest for both partners. Both are at their best, and love and attraction come naturally. This “honeymoon phase” lasts longer for some couples than for others.
Underlying all relationship processes are the competing biological drives for individuality and togetherness. Individuality is the need to be independent and autonomous. The togetherness drive is represented by the needs for belonging, agreement and acceptance. The competing drives for individuality and togetherness play out within individuals and between them. Ultimately, these competing drives generate the tension in relationships.
Tension may be triggered by stressful events external to the relationship, when relationship intensity increases by moving in together or getting married, or because the partners carry a lot of internal anxiety from the outset. At some point, this tension will expand beyond the capacity of the couple to contain it between them.
When tension between any two people gets high enough they respond in predictable, biologically rooted ways:
- Emotional distance. The partners stop dealing directly with each other. They may watch their words, ignore difficult topics, and otherwise edit and audit their behavior to avoid discomfort. If the distance itself creates enough discomfort, maladaptive behavior like drinking or other addictions may increase. Symptoms of depression, anxiety, or even physical illness may also show up or increase as a result of emotional distance. Ironically, conflict is also a sign of emotional distance and an (unsuccessful) attempt to deal with it.
- Relationship triangles. It is human nature to “triangle in” a third person when tension gets too high for a twosome. Anytime two people are talking about a third person who is not present, that’s an emotional triangle. Gossip and bullying are examples of triangles when they become problematic. So is over-focus on a child, excessive jealousy, or arguing repeatedly about a specific person or persons outside the marital relationship.
Emotional distance and relationship triangles are the concepts that explain why people have affairs. The excuses people give for cheating-boredom, lack of sex, mid-life crisis, etc-are all manifestations of these two relationship processes.
Some people are more likely to react to the relationship process by having affairs, just like some people are more likely to react to it by drinking, worrying, working too much, or whatever it is they do when they are uncomfortable enough. This is an explanation for the behavior, not an excuse. Affairs inevitably cause a lot of damage and can and should be avoided.
It is important to understand the real cause of affairs so that you can develop the tools to do your part to affair-proof your relationship or, if an affair has already occurred, to heal from it.
Read the entire 4 part series:
Part 1: 4 Common Myths about Infidelity
Part 2: Universal Truths about Affairs
Part 3: Affair-Proof your marriage, 4 Do’s and 4 Don’ts
Part 4: Understanding Marital Infidelity:The Key to Healing From an Affair