According to research, cheating is rarely a simple affair. There are many reasons why people become unfaithful, and the patterns are more complex than common stereotypes suggest. A fascinating study from 2021 sheds some light on these motivations.

The investigation included 495 people (87.9 percent of whom identified as heterosexual), who were recruited through a participant pool at a large U.S. university and through relationship-related Reddit message boards.

The participants admitted to cheating in their relationship and answered the question at the root of the mystery: why did you do it? An analysis revealed eight key reasons: anger, self-esteem, lack of love, low commitment, need for variety, neglect, sexual desire, and situation or circumstance. These motivations not only influenced why people cheated but how long they did so, their sexual enjoyment, their emotional investment in the affair, and whether their primary relationship ended because of it.

Though most cheating involves sex, it is rarely just about the act itself. Most participants felt some form of emotional attachment to their affair partner, but it was significantly more common in those who reported suffering from neglect or lack of love in their primary relationship.

Around two-thirds of participants (62.8 percent) admitted they felt affection toward their new partner. About the same proportion (61.2 percent) engaged in sexually explicit dialogue with them. Roughly 4 out of 10 (37.6 percent) had intimate conversations, while 1 in 10 (11.1 percent) said, “I love you.”

Those who reported feeling less connected to their primary partner experienced greater emotional intimacy in the affair, which might be a way of fulfilling that need. Additionally, when infidelity was linked to a lack of love, individuals found the experience more intellectually and emotionally satisfying.

Participants' satisfaction with sex differed depending on the reason for their affair. People reported feeling more sexually fulfilled when they cheated because of desire, lack of love, or a need for variety. Much of the sexual activity was limited to kissing (86.7 percent) and cuddling (72.9 percent). Interestingly, the study found that only half of the cheaters reported having vaginal intercourse.

The reason for the infidelity also had a great impact on its length. In some cases, the relationship was a brief tryst, while others were a longer and deeper attachment. Those who cheated because of anger (such as a wish to “seek revenge”), lack of love, or need for variety had a longer affair, while those motivated by the situation (such as those who were “drunk” or “overwhelmed” and “not thinking clearly”) ended it sooner. Women also had longer affairs, on average, than men.

In the end, only a third of participants ultimately admitted to their primary partner that they were cheating on them. Women were more inclined to fess up than men. Also, those who came clean were more likely to have cheated out of anger or neglect rather than sexual desire or variety. This suggests that their confession could have been a form of retribution and a way to exact revenge instead of a way to clear their conscience. The participants who confessed were more likely to form a committed relationship with the affair partner, too.

So does an affair really end a relationship? Ultimately, the fate of the participants' primary relationship depended less on the act itself and more on what motivated it.

Cheating was more likely to end a relationship when it arose from anger, lack of love, low commitment, or neglect and it was less likely to do so when the infidelity was circumstantial.

Surprisingly, only one in five (20.4 percent) of relationships ended because of the affair. The same number of couples (21.8 percent) stayed together despite their primary partner finding out, while slightly more (28.3 percent) stayed together without their partner discovering their infidelity. The remaining relationships broke up for other reasons.