Direct answer: Science can flag probabilities, not destinies. Certain histories and traits raise the odds that someone will cheat again, and relationship quality shifts those odds further. Yet researchers describe infidelity as only somewhat predictable. No test, questionnaire, or algorithm can tell you whether a specific partner will stray.
What the evidence offers is calibration: it tells you which signals deserve weight during partner choice, and which are noise.
Singles in the US and Canada ask it. So do couples in Europe, East Asia, and the Middle East. Can you predict infidelity before you promise exclusivity?
Does Past Infidelity Predict Future Infidelity?
“Adults who reported extra-dyadic sex in a first relationship were three times more likely to report it again in a subsequent relationship.” (Knopp et al., 2017)
That finding comes from a longitudinal study of 484 adults followed through two consecutive relationships. The pattern held regardless of gender or marital status. People who knew a first partner had cheated were twice as likely to report the same from the next partner. Those who merely suspected were four times more likely to suspect again.
The design matters here. Participants were tracked over time rather than asked to recall distant events. That strengthens the case that prior behavior carries real information about future behavior. Still, a tripled likelihood is a relative risk, not a forecast about any one person.
The fair reading is simple: past infidelity is a meaningful risk marker rather than a fixed verdict.
Which Personal and Sexual Traits Matter?
“Sexual personality traits predicted infidelity in both sexes, while low relationship happiness and low sexual-value compatibility predicted it in women.” (Mark et al., 2011)
That study surveyed men and women who described their relationships as monogamous. Among the men, 23.2% reported cheating in the current relationship. Among the women, the figure was 19.2%.
The strongest predictors were not demographics. They were sexual excitation, inhibition tied to performance concerns, inhibition tied to consequences, and regretful sex during negative mood.
Notice what this implies for partner choice. How someone responds to sexual arousal and restraint says more than marital status or religiosity. For women, low relationship happiness and mismatched sexual attitudes added predictive weight. Compatibility in sexual values deserves direct conversation, not assumption.
The practical takeaway: sexual temperament and value alignment are legitimate compatibility criteria.
How Much Does Relationship Quality Help Predict Infidelity?
“Infidelity was only somewhat predictable, and interpersonal factors such as relationship satisfaction, love, desire, and relationship length were the most predictive.” (Vowels et al., 2022)
That analysis covered two studies with 1,295 participants and tested both online and in-person infidelity. Relationship satisfaction, love, desire, and relationship length outperformed individual traits. In other words, the state of the bond itself carries the most signal.
This is where prediction stays limited. Two couples can share identical histories and traits yet diverge based on how they handle dissatisfaction. Research has not yet settled how these forces interact over decades. Early attention to relationship difficulties appears protective, but no model captures every trajectory.
For couples, that makes relationship quality the most actionable predictor available.
What Does This Mean When Choosing a Life Partner?
Ask about past relationships without turning the conversation into an interrogation. Listen for how someone describes an ex: with accountability, contempt, or avoidance. A person who names their own contributions to a breakup is showing you their repair style. Someone who frames every ex as the problem is showing you something else.
Discuss sexual values before commitment, including frequency, exclusivity expectations, and how you each handle mismatched desire. Then watch how dissatisfaction gets handled in real time. Early repair of small ruptures tells you more than any confession extracted under pressure.
Timing matters too. These conversations land better in the early months, before either partner has much to defend. Treat them as a shared inventory of expectations rather than a test one person must pass. Couples who can hold this kind of talk calmly are rehearsing the same skill that protects them later.
Professional Experience: What Relationship Counselors See
The studies above echo two themes that premarital counseling stresses. Dissatisfaction left unspoken is one. Sexual expectations never discussed before commitment is another. The emotional toll of betrayal can be severe.
One study followed unmarried young adults who had recently been betrayed. Of them, 45.2% showed symptoms suggesting probable infidelity-related PTSD (Roos et al., 2019).
When Does Professional Help Make Sense?
Help makes sense when the same disagreement keeps returning without resolution. It makes sense when one partner carries anxiety about the other’s history. It makes sense before engagement, not only after crisis. A private 20-minute conversation with MarryClub VIP can clarify what a matchmaking process should explore with you.
Frequently Asked Questions
Can one past affair predict another?
A prior affair roughly triples the likelihood of repetition in the next relationship, according to longitudinal data (Knopp et al., 2017). Treat that as a relative risk signal, not a certainty for any individual.
Do demographics predict cheating better than personality?
Not in this research. Sexual personality traits and, for women, relationship happiness and sexual-value compatibility outperformed marital status and religiosity in a large survey (Mark et al., 2011). Focus on temperament and compatibility instead.
Is infidelity predictable overall?
Only somewhat. Relationship satisfaction, love, desire, and relationship length were the strongest predictors across two studies (Vowels et al., 2022). No model reliably forecasts individual behavior.
How painful is betrayal, really?
It can be serious. In a group of betrayed unmarried young adults, 45.2% reported symptoms consistent with probable infidelity-related PTSD (Roos et al., 2019). Those symptoms were linked to depression. The stakes justify careful partner selection.
Conclusion
Instead of asking whether someone will cheat, ask how they behave when disappointed. Choose partners who raise problems early and repair them visibly. That single habit, practiced across years, may matter more than any prediction science can offer.
Sources
- Knopp K, Scott S, Ritchie L, Rhoades GK, Markman HJ, Stanley SM. Once a Cheater, Always a Cheater? Serial Infidelity Across Subsequent Relationships. Arch Sex Behav. 2017;46(8):2301-2311. PMID: 28785917 · DOI: 10.1007/s10508-017-1018-1
- Mark KP, Janssen E, Milhausen RR. Infidelity in heterosexual couples: demographic, interpersonal, and personality-related predictors of extradyadic sex. Arch Sex Behav. 2011;40(5):971-982. PMID: 21667234 · DOI: 10.1007/s10508-011-9771-z
- Vowels LM, Vowels MJ, Mark KP. Is Infidelity Predictable? Using Explainable Machine Learning to Identify the Most Important Predictors of Infidelity. J Sex Res. 2022;59(2):224-237. PMID: 34431739 · DOI: 10.1080/00224499.2021.1967846
- Roos LG, O'Connor V, Canevello A, Bennett JM. Post-traumatic stress and psychological health following infidelity in unmarried young adults. Stress Health. 2019;35(4):468-479. PMID: 31199042 · DOI: 10.1002/smi.2880
This article is also available in Persian: Persian version.