Understanding why people cheat matters more than most of us want to admit, whether we’re trying to make sense of our own relationship or simply curious about human behavior. Research consistently shows that infidelity is rarely just about sex, even though that’s the assumption most people default to.
Most people cheat for reasons that have little to do with sex itself. A landmark study of nearly 500 people who admitted to cheating found eight key motivations, most of which didn’t involve sex at all, including anger, lack of love, low commitment, esteem, situation, and neglect.
Infidelity is far more common than most people assume. The lifetime prevalence of infidelity is approximately 20 to 25 percent of marriages, with men and women cheating at similar rates.
The numbers shift depending on the relationship type. A quarter of married and cohabiting young men and women reported that either they, their partner, or both had sex with someone else, and young men were more likely to report it than young women.
Some infidelity is driven by a desire to get even. This motivation includes cheating out of a desire to get back at a partner who had cheated or was suspected of having done so, or to get back at a partner for something else upsetting.
This is the motivation most people assume dominates, but it’s only one piece. Some reported feeling unsatisfied with the sex in their relationship and wanting to explore something novel.
Falling out of love with a partner is a commonly cited driver. Falling out of love, seeking variety, and feeling neglected were the most commonly cited reasons among people who cheated.
Feeling unseen by a partner shows up again and again in the research. Seventy percent of participants revealed that feeling neglected was at least moderately tied to their cheating behavior.
Sometimes the relationship itself was never fully defined as exclusive. Low commitment means one partner was not as committed as the other, or both partners didn’t have a shared understanding that their relationship was exclusive.
Cheating can serve as an emotional boost for some people. Infidelity in romantic relationships isn’t just about opportunity, it often starts with a lack of self-worth and an almost desperate need for approval.
Context and circumstance play a bigger role than many expect. Some people found themselves in scenarios outside the norm, such as being intoxicated, on vacation, or under high stress.
The desire for novelty is distinct from simple sexual dissatisfaction. When people cheated due to variety, their affairs tended to be longer, similar to those motivated by anger or lack of love.
This is one of the most puzzling parts of infidelity research. Many people stray not because they want to leave their relationship, but because something deeper is at play, and many affairs happen not out of dissatisfaction but for more complex psychological reasons.
Even self-reported happiness doesn’t rule out infidelity. In one study of 300 unfaithful partners, 56% of men and 34% of women rated their relationship with their regular partner as happy or even very happy.
The brain’s chemistry offers part of the explanation. Romantic love transitions from a dopamine-fueled motivation system in early relationships to a more stable, attachment-driven state supported by oxytocin and vasopressin, and some people struggle with the loss of that early-stage excitement.
| Factor | Men | Women |
|---|---|---|
| Primary motivator | Sexual desire, variety, situational forces | Neglect, emotional dissatisfaction |
| Emotional vs. physical | More often physical-first | More often emotional-first |
| Affair duration | Shorter on average | Longer on average |
| Common driver | Opportunity, novelty | Feeling unseen or unheard |
Men were more likely to report being motivated to cheat by sexual desire, variety, and situational forces, while women were more likely to be motivated by neglect.
Even when men cite sexual motives, the picture is more complex than it seems. Even when men reported a sexual motivation, it rarely existed in isolation, and it was often intertwined with perceptions that their partner was emotionally negligent or inattentive.
Some people are statistically more prone to infidelity based on personality traits alone. Individuals low in conscientiousness are more likely to cheat, and this tendency increases if their partner also has low conscientiousness, often showing up as disorganization, carelessness, and unreliability.
Certain other traits also correlate with higher infidelity rates. Individuals low in agreeableness and high in extraversion are more prone to infidelity, along with women high in neuroticism and individuals with pronounced dark personality traits such as narcissism.
Attachment history plays a role too. Insecure attachment styles, often stemming from childhood neglect or inconsistency, can lead to difficulties maintaining trust and intimacy in adult relationships, increasing vulnerability to cheating.
Cheating rarely happens in a vacuum. Decreased satisfaction in a present relationship is closely related to infidelity among married people.
Small moments of disconnection can add up over time. One of the worst things in a marriage is when a person ignores their partner’s attempt to connect, and rejected bids can cause emotional neglect and sexual dissatisfaction, ultimately making infidelity more likely.
Not all infidelity looks the same, and the emotional component often matters more than people expect. Around two thirds of participants expressed affection toward their new partner, and those who felt less connected to their primary partner experienced greater emotional intimacy in the affair.
| Affair Type | Common Driver | Typical Duration |
|---|---|---|
| Primarily physical | Sexual desire, opportunity | Often shorter |
| Primarily emotional | Neglect, lack of love | Often longer |
| Mixed emotional-physical | Combination of unmet needs | Varies widely |
Brain chemistry and genetics may also play a supporting role. A tendency to cheat appears to be moderately heritable, likely due to inherited personality traits or libido levels, and higher levels of testosterone have been linked to a greater inclination toward risk-taking behaviors, including cheating.
| Explanation | Strength | Limitation |
|---|---|---|
| Emotional neglect | Explains most cited motivations | Doesn’t account for purely situational cheating |
| Personality traits | Backed by consistent research | Doesn’t guarantee someone will cheat |
| Biological/hormonal | Offers a physiological layer | Doesn’t excuse behavior or predict it alone |
| Situational opportunity | Explains context-driven cheating | Less relevant for long emotional affairs |
| Attachment style | Connects to childhood patterns | Not deterministic, many secure people still cheat |
Many couples do stay together, though outcomes vary over time. Between 60% and 75% of couples stay together after infidelity is discovered, at least initially, but that number drops closer to 50% when researchers follow those couples over several years.
How the person who cheated responds matters significantly. Recovery has a lot to do with the empathy and contrition of the cheater, whether they take responsibility, and whether they own up to the hurt they caused.
Understanding your partner’s reason for cheating, if it happens, matters for what comes next. Professional help through therapy and counseling is essential for addressing unresolved trauma and the aftermath of infidelity, and open, honest communication is critical for rebuilding trust.
Love doesn’t always meet every emotional or physical need, so people can cheat despite genuine love, often due to unmet needs, personal insecurity, or a desire for novelty.
No. Research shows most motivations for infidelity are not primarily about sex, with emotional neglect and lack of connection being far more common drivers.
Yes. Men more often cite sexual desire, variety, and situational forces, while women more often cite neglect and emotional dissatisfaction.
Yes. Studies show a significant percentage of people who cheated described their relationship as happy at the time.
Some research suggests a tendency toward infidelity is moderately heritable, likely tied to inherited personality traits or libido levels.
Yes. A need for validation and approval is a documented motivation, especially when someone feels undervalued in their primary relationship.
Traits like low conscientiousness, low agreeableness, and high extraversion are consistently linked to higher rates of infidelity in research.
Yes. Insecure attachment styles linked to childhood neglect or inconsistency can make it harder to maintain trust in adult relationships.
Many people consider emotional affairs a form of betrayal, even without physical involvement, since they often involve intimacy and connection outside the relationship.
Research estimates roughly 20 to 25 percent of married individuals in the U.S. have been unfaithful at least once.
Many couples stay together initially, though long-term recovery depends heavily on accountability, communication, and often professional support.
Anger-driven infidelity often stems from a desire to retaliate against a partner’s own betrayal or hurtful behavior.
Opportunity is a contributing factor, especially situational cheating during travel, intoxication, or high-stress periods, but it usually combines with other motivations.
Both occur, and research shows emotional affairs tend to last longer, while purely physical affairs tend to be shorter.
It refers to behaviors that fall short of traditional infidelity, like flirting with a coworker, but that may still feel like a betrayal to a partner.
Yes. Couples therapy and individual counseling are commonly recommended to process trauma, rebuild communication, and restore trust.
Research suggests overall infidelity rates haven’t significantly increased since before dating apps became widespread, despite common assumptions.
Affairs motivated by anger, lack of love, or variety tend to last longer, while situational affairs are often shorter.
Research shows neglect is cited more often than sexual dissatisfaction alone, especially among women.
Yes. Higher testosterone levels have been linked to increased risk-taking behavior, including infidelity, particularly in men.
Infidelity is rarely a single-cause behavior. It usually reflects a mix of emotional neglect, personality traits, relationship dynamics, and sometimes situational pressure, more than a simple desire for sex.
Understanding these research-backed reasons doesn’t excuse cheating, but it does offer a clearer, more compassionate lens for making sense of why it happens and what healing might require afterward.