Cheating changes the person who does it, not just the person who gets cheated on. The effects range from a surprising initial thrill to lasting shifts in self-perception, brain chemistry, and future relationship patterns. Most people assume they’d feel terrible after being unfaithful, but the psychological reality is more complicated and, in some ways, more troubling than simple guilt.
The Cheater’s High Is Real
Most people predict they would feel guilt, shame, or anxiety after cheating. That prediction is often wrong. Research published through the American Psychological Association found that people who cheat frequently experience a boost in positive feelings, a phenomenon researchers call the “cheater’s high.” This spike in self-satisfaction comes from the thrill of getting away with something, and it occurs without a corresponding increase in negative emotions like guilt.
This matters because it helps explain why cheating doesn’t always feel as bad as people expect it to, which in turn makes it easier to do again. The cheater’s high tends to be strongest when the person doesn’t have to witness the direct harm their actions cause. In the context of infidelity, that’s often the case: the betrayed partner doesn’t know, so the cheater is insulated from seeing the damage in real time.
How Cheaters Manage the Guilt
When guilt does show up, cheaters don’t just sit with it. They actively work to reduce the internal conflict between “I’m a good person” and “I did something that contradicts my values.” This tension is called cognitive dissonance, and it’s psychologically uncomfortable enough that the brain scrambles to resolve it.
Research on infidelity perpetrators has identified two main strategies. The first is modifying beliefs and attitudes: reframing the cheating as justified, minimizing its significance, or deciding that monogamy itself is unreasonable. The second is blaming the primary relationship, pointing to dissatisfaction, unmet needs, or a partner’s shortcomings as the real cause. Both strategies protect the cheater’s self-image, but they do so by distorting how the person sees their relationship, their partner, and their own moral standards.
A third strategy, denial of responsibility, also proves effective at reducing psychological discomfort. People tell themselves they were drunk, lonely, or “not in their right mind.” These rationalizations work surprisingly well in the short term. Studies tracking cheaters over time found that those who used attitude change, self-concept reshaping, or denial of responsibility reported significantly less psychological distress afterward compared to those who didn’t employ these strategies.
What Happens in the Brain
Infidelity triggers the same reward circuitry involved in addiction. The brain’s pleasure center fires most intensely not during the affair itself but during the anticipation: the secret texts, the planning, the stolen moments of contact. Novelty is one of the most potent triggers for the brain’s reward system, and an affair partner delivers it in concentrated form. Not because they’re objectively better than the committed partner, but because they’re new.
This creates a measurable state sometimes called “affair fog,” where surges of reward chemicals genuinely impair judgment and rational thinking. Three systems activate at once: the reward system creates motivation toward the affair partner, stress hormones spike arousal and obsessive focus, and the brain chemicals that normally regulate mood and compulsive thinking drop sharply, producing a pattern that resembles obsessive-compulsive states. The result is that otherwise clear-thinking people make choices they later struggle to explain.
With repeated cheating, the brain adapts through the same tolerance mechanism seen in substance addiction. Receptors that process reward become less sensitive over time, meaning each subsequent affair requires more intensity, more risk, or more novelty to produce the same feeling. This is one reason serial infidelity tends to escalate rather than plateau.
Cheating Reshapes Self-Identity
One of the less obvious effects of infidelity is how it changes the cheater’s sense of who they are. Both online and offline infidelity predict measurable shifts in self-concept. Sometimes this takes the form of self-expansion: the person feels more interesting, more desirable, more alive. They may genuinely believe the affair has made them a better version of themselves. Other times, the shift is negative, with people taking on traits they don’t admire or shedding parts of their identity they previously valued.
The direction of that change often depends on which rationalization strategy the person uses. Those who successfully reframe the affair as a form of personal growth tend to report self-concept improvement. Those who can’t fully rationalize it experience what researchers describe as self-contraction and self-adulteration, a sense that they’ve become smaller or more corrupted as a person. Perpetrators of infidelity consistently report struggling with guilt, regret, and the uncomfortable need to justify their actions, emotions that can linger well beyond the affair itself.
Men and Women Experience Guilt Differently
The type of infidelity that triggers guilt varies by gender. Men feel guiltier after sexual infidelity, while women feel guiltier after emotional infidelity. This pattern held in direct comparisons: men rated imagined sexual cheating as a significantly stronger source of guilt (averaging 3.4 on a 5-point scale) than women did (2.7). Women rated emotional cheating higher (3.2 versus 2.6 for men).
Both men and women believed their partners would have a harder time forgiving sexual infidelity than emotional infidelity. Women were also significantly more likely than men to believe their sexual infidelity would lead to a breakup. These perceptions shape the emotional aftermath: the type of cheating a person believes is most damaging tends to generate the most internal distress when they’re the one who commits it.
Why Cheating Tends to Repeat
A study tracking 1,600 individuals across multiple relationships found that someone who has cheated before is three times more likely to cheat again. Several of the mechanisms above help explain why.
The rationalization strategies that reduce guilt after the first affair don’t disappear. Once a person has successfully reframed their values to accommodate cheating, those altered beliefs carry forward into new relationships. The brain’s reward tolerance means the emotional baseline keeps shifting, making stable relationship satisfaction harder to maintain. And the self-concept changes that come with infidelity can become permanent features of a person’s identity: someone who has internalized the idea that they’re “the kind of person who needs more” is primed to act on that belief again.
Some people also carry a genetic predisposition. A specific variant in dopamine receptor genes produces receptors that bind less efficiently, creating what amounts to a built-in reward deficit. People with this variant need stronger stimulation across many areas of life to reach the same satisfaction threshold others achieve from moderate experiences. This doesn’t make infidelity inevitable, but it does lower the neurological barrier to novelty-seeking behavior.
The Long-Term Emotional Cost
Even when cheaters successfully rationalize their behavior, the strategies they use come with hidden costs. Rewriting your beliefs to justify infidelity means your moral framework becomes increasingly flexible, which can erode trust in your own judgment over time. Blaming your partner for your choices creates a distorted view of the relationship that makes genuine intimacy harder. Denying responsibility prevents the kind of honest self-reflection that personal growth requires.
Perpetrators of infidelity consistently describe dealing with negative self-conscious emotions: guilt that surfaces unpredictably, regret that intensifies with distance from the affair, and an ongoing need to justify actions they can’t fully reconcile with their self-image. The cheater’s high fades. The rationalizations hold for a while. But the person who emerges from sustained infidelity has, in measurable ways, a different brain, a shifted identity, and a statistically higher chance of repeating the pattern.