Infidelity Quiz: Is Your Partner Cheating?

Fifty-six percent of men who had affairs were happy in their marriage, according to a study by Helen Fisher, PhD, a biological anthropologist at Rutgers University and the author of Why Him? Why Her?and Why We Love. By comparison, only 34% of women who had affairs were happy or very happy in their marriage.

Men are more likely to give sexual motivations for infidelity and less likely to fall in love with an extramarital partner, Fisher tells WebMD. "Women are more interested in supplementing their marriage or jumping ship than men are. For men, it is a secondary strategy as opposed to an alternate."

Experts say that most often, men and women have different reasons for being unfaithful. Men search for more sex or attention, and women look to fill an emotional void.

Women tend to have an emotional connection with their lover and are more likely to have an affair because of loneliness.

Although infidelity is the main reason unmarried couples who are living together split up, the same is not true of married couples. Married couples often cite being incompatible or unable to communicate as the cause of their divorce.

Statistics from the American Association for Marriage and Family Therapy suggest that 25% of husbands report having had sex outside of their marriage. When emotional affairs or sexual intimacy without intercourse (such as kissing) are included, the number jumps to 45%.

Statistics from the same organization, the American Association for Marriage and Family Therapy, say only 15% of wives report having had sex outside of their marriage. Like men, the number does go up when you include emotional affairs or things like kissing -- 35% of wives admit to that.

Experts say it's important to address concerns about infidelity early, even if you have no clear proof that your partner is having an affair. Whether or not it happened, the couple has work to do on their trust and communication so they can move forward in their relationship.

And what about "spying" on your partner? Don’t do it. You may be able to prove there was an affair, but you’ll never prove there wasn't. And you’ll destroy the trust and communication you need to have a good relationship. That can be more damaging to a marriage than sexual infidelity itself.

A National Marriage Project study found that highly educated people are less likely to be unfaithful than their less educated peers. In the 2000s, 13% of people with a college education said they had sex outside their marriage, compared to 19% of those who were moderately educated and 21% of those with the least education (high school dropouts).

A Cornell University study on income and infidelity found that women are least likely to stray when they depend on their husband’s income. They may have fewer opportunities to cheat and may decide it isn’t worth it because their livelihood may be at risk.  

The same Cornell University study found that men who were completely dependent on their wife’s income were five times more likely to cheat than men who contributed equally.

It’s not just money, though. When age, education level, income, religious attendance, and relationship satisfaction were taken into account, there wasn’t any difference between men who depended on their wife’s income and those who didn’t.

Ironically, the same Cornell University study found that men who bring home most of the household income are also more likely to cheat. Men were least likely to cheat when their partners made about 75% of their incomes.

Experts say partners who cheat often begin paying more attention to their appearance, criticizing their spouses, and/or giving unsolicited gifts. When one partner is constantly critical, they may be setting up the other partner to be the one at fault. A partner who gives gifts may be feeling guilty.

Laws against adultery remain on the books in many states. Of course, they are rarely enforced.

It’s not proof, and genetics aren’t destiny. But there’s some evidence that genes linked to sensation-seeking behaviors, such as drinking alcohol or gambling, may also be associated with sexual promiscuity and infidelity.

The study focused on the DRD4 gene, which is associated with reward and feeling good. People with a variation of that gene were more likely to commit infidelity or be promiscuous; 50% of people with the variation reported being unfaithful, compared with 22% of people who didn’t have the variation.

The first priority of couples coping with infidelity should be building trust again. That happens best if they seek help together. While seeing an individual therapist also may help, it could build a wall of secrecy and privacy between them and lead to further alienation.

The betrayed person should set the timetable for recovery. While the person who cheated may be eager to put the past behind them, they need to honor the other person’s timetable.