Spouses cheat for a wide range of reasons, and rarely is it just one. A University of Maryland study surveying 495 adults who admitted to infidelity identified eight distinct motivations, from anger and neglect to self-esteem issues and pure opportunity. Understanding these drivers won’t make infidelity less painful, but it can help make sense of something that often feels senseless.
The Eight Core Motivations
The University of Maryland research team analyzed responses to nearly 80 questions and found that unfaithful partners were driven by some combination of these factors: anger (wanting revenge for a partner’s betrayal), sexual desire (feeling unsatisfied and wanting something new), lack of love (falling out of love or losing passion), neglect (not receiving enough attention, love, or respect), low commitment (mismatched investment in the relationship), situation (being intoxicated, on vacation, or under unusual stress), esteem (seeking a sense of self-worth or independence), and variety (wanting sexual experiences with multiple partners).
These motivations don’t exist in isolation. Someone feeling neglected may also be experiencing low self-esteem, and a stressful situation like a work trip can lower the threshold for acting on feelings that already existed. The study makes clear that infidelity is almost always a convergence of factors rather than a single cause.
How Gender Shapes the “Why”
About 20% of married men and 13% of married women report having sex with someone other than their spouse. But the gap narrows considerably when emotional affairs are included: roughly 92% of women who were unfaithful described their affair as emotional, compared to about 79% of men. The types of connection people seek outside their marriage tend to differ.
Men more often cite sexual dissatisfaction, a desire for variety, or a need for attention as primary drivers. Women more consistently describe emotional emptiness. As marriage therapist Winifred Reilly has noted, the refrain she hears from women is remarkably consistent: “I was lonely, not connected, I didn’t feel close to my partner, and I was taken for granted.” Anthropologist Helen Fisher’s research supports this pattern, finding that women are more likely to develop an emotional bond with an affair partner and more likely to cite loneliness as the catalyst.
These are tendencies, not rules. Plenty of men cheat because they feel emotionally disconnected, and plenty of women cheat for purely physical reasons. But the broad patterns help explain why men and women also react differently to discovering a partner’s affair. Research shows 60% of men say physical infidelity is worse than emotional infidelity, while 83% of women say the opposite.
Personality Traits That Increase Risk
Not everyone in an unhappy marriage cheats, and not everyone who cheats is in an unhappy marriage. Personality plays a significant role. Studies using the “Big Five” personality framework have found consistent patterns: people who cheat tend to score higher in neuroticism (emotional instability), extraversion, and openness to new experiences. They score lower in agreeableness and conscientiousness.
When researchers drilled into specific sub-traits, the strongest predictor was social assertiveness, a facet of extraversion that involves confidence and dominance in social settings. Excitement-seeking also contributed, though to a lesser degree. On the protective side, a strong sense of duty (a facet of conscientiousness) was associated with greater faithfulness. People with avoidant attachment styles, those who instinctively pull away from emotional closeness, are also at elevated risk, likely because they struggle with the vulnerability that long-term intimacy requires.
The so-called “dark triad” traits of narcissism, Machiavellianism, and psychopathy have also been linked to infidelity, though these represent more extreme personality profiles. For most people, the risk factors are subtler: a tendency toward impulsivity, a high need for novelty, or difficulty tolerating emotional discomfort.
Biology and the Novelty Drive
Some of the predisposition toward infidelity appears to be biological. Vasopressin, a hormone involved in trust, empathy, and sexual bonding, plays a measurable role. Animal studies have shown that blocking vasopressin receptors in naturally monogamous prairie voles disrupted their pair-bonding behavior, while introducing the vasopressin gene into non-monogamous voles made them behave more monogamously. Human brains are far more complex, but the same hormone system operates in us.
A 2010 study found that a variation in the dopamine receptor gene DRD4, sometimes called the “thrill-seeking gene,” was linked to higher rates of infidelity. Everyone carries this gene, but people with more copies of a particular variant need more dopamine to feel satisfied, pushing them toward novel and risky behaviors. The same genetic variation has been associated with higher rates of gambling and alcohol problems. Among the 181 young adults in the study, those with the longer variant of DRD4 were significantly more likely to have cheated. None of this means infidelity is predetermined, but it does help explain why some people find monogamy more effortful than others.
Where Affairs Actually Start
Opportunity matters enormously. The workplace remains one of the most common settings for affairs to begin: 48% of U.S. employees report having been involved in a workplace romance at some point in their careers, and 81% have either had one or know a colleague who has. The combination of daily proximity, shared goals, and emotional investment in projects creates fertile ground for connection that gradually crosses boundaries. Most of these relationships (72%) develop between people at the same professional level, though about 22% involve a manager and a direct report.
Social media has introduced an entirely new category of risk. Platforms make it effortless to reconnect with former partners, maintain ambiguous friendships, and engage in low-level flirtation that slowly escalates. Research has found that people who score higher on social media addiction also score higher on social media-related infidelity. The mechanism is partly about reduced inhibition: people tend to be bolder and more candid online than they would be face to face. What starts as a casual comment on an old friend’s post can evolve into private messaging, emotional intimacy, and eventually a full affair. Studies have also linked heavy social media use to increased jealousy and surveillance between partners, eroding the trust that keeps relationships stable.
Relationship Satisfaction Is Only Part of the Story
It’s tempting to assume that cheating always signals a broken marriage, but the data is more nuanced. Research published through the American Psychological Association found that couples dealing with infidelity were significantly more distressed and reported more depressive symptoms at the start of therapy than other couples. Yet interestingly, infidelity was not consistently linked to sexual dissatisfaction. Many unfaithful partners reported adequate or even satisfying sex lives. The disconnect was often emotional rather than physical: feeling unseen, unappreciated, or emotionally distant from a spouse.
The same research offered a somewhat hopeful finding. Couples who experienced infidelity but stayed together and worked through it showed relationship satisfaction levels comparable to couples who had never dealt with infidelity. In other words, the affair itself didn’t permanently damage the relationship’s potential; it was how the couple responded that determined the outcome.
What Happens to the Marriage After
Between 60% and 75% of couples stay together after infidelity is discovered, at least initially. That number drops closer to 50% when researchers follow couples over several years. The early decision to stay is often driven by practical concerns (children, finances, shared history) as much as by forgiveness or renewed commitment. Long-term survival depends on whether both partners can rebuild trust, which typically requires the unfaithful partner to take full accountability and the betrayed partner to eventually move from justified anger toward a willingness to re-engage.
Couples who divorced after infidelity reported the lowest relationship satisfaction scores of any group studied, averaging well below clinical thresholds for a healthy relationship. But couples who stayed and actively worked on repairing the damage didn’t just survive. They reached satisfaction levels that were statistically indistinguishable from couples who had never experienced an affair. The path between those two outcomes is difficult, often taking years, but the data suggests it is genuinely possible.