The reasons why men cheat in a relationship are often different than the reasons why women cheat. A man's reason for cheating can include genetics, a sense of challenge, self-esteem and a lack of interest in their current relationship. None of these reasons are justifiable but it is very helpful to understand them.

Genetics may play a factor. There is a theory that some men are more susceptible because of high testosterone levels and high sex drive. The theory suggests that men are programmed from prehistoric times to ensure the survival of the species by being sexual with as many women as possible.

Certainly some men have very high sex drives, but this is no reason for unfaithfulness to a partner in today's world of overpopulation and rampant divorce. Just like any other health issue, there are better ways available than giving in to the urges.

Another reason men cheat is the sense of challenge. They enjoy getting away with the affair, as well as the challenge of finding other women with whom to cheat. They enjoy the conquest more than anything.

Sure they enjoy the sexuality of the affair, but the pursuit, sneaking around, and the orchestration of the affair give the adrenaline rush that is more important than either the affair or the current relationship.

Men also cheat because of competition with other men. If their friends are single or cheating on their partners the man may feel he has to keep up with his friends.

This competition also fits in with the ego boost men will usually feel when in an affair. They feel desirable, powerful, and like a winner. They take pride in their ability to attract women and don't care that doing so may destroy their relationship. Often the excitement of the chase is more important than the conquest.

Sometimes, just knowing that other women find them desirable is enough of a stroke that an actual affair is not even necessary. In general, it is a lack of self-esteem that drives them to reaffirm their attractiveness and desirability.

There usually is some difference between men who repeatedly cheat and those who have a single affair and then are rather surprised to find themselves in such a situation. The last reason for cheating is more likely to apply to this second group.

A man who is in a undesirable relationship is an affair waiting to happen. If the relationship has begun to wane and the man no longer feels the same attraction, he may find himself moving from boredom toward the excitement of another woman. It often starts as an innocent friendship that goes too far.

While the wise thing for such a man to do would be to either end the deteriorating relationship or go to work on making it better, many men hold on to it for safety while becoming involved with someone else.

All these reasons contribute to why men cheat: genetics, competition, self-esteem, and boredom. None justify the breaking of faith with a partner and the resulting loss of true emotional intimacy. However, understanding the problem helps us move toward the solutions in future articles.