Adultery and Its Aftermath: How Affairs Begin, Who They Hurt, and How Repair Happens.
All research cited is peer-reviewed.
Few events shake a family as deeply as the discovery of an affair. It is common, often misunderstood, and its effects ripple well beyond the couple — to children, to the affair partner, and across generations. This piece draws together what the research tells us about how affairs start, the damage they cause, and what genuinely helps people recover.
How common is adultery?
Prevalence is hard to pin down because people under-report, and definitions vary.
The most robust data come from the US General Social Survey. Between 2000 and 2016, lifetime prevalence of extramarital sex was 21.4% for married men and 13.4% for married women.
In any given year, an average of 4.1% of married men and 2.0% of married women reported cheating.
One caveat: the survey does not separate infidelity from consensually open marriages, so these figures may overestimate it.
Despite how common it is, most people in every group surveyed disapproved of infidelity.
What counts as an affair?
Infidelity is usually defined as secret emotional, sexual or romantic behaviour that breaches the exclusivity a relationship assumes. Researchers subdivide it into sexual, emotional, combined and internet infidelity.
People’s judgements of what counts are broad: sexting and sexualised social media contact are rated much like cybersex and physical sexual infidelity.
Crucially, couples routinely miscommunicate about monogamy, and some disagree about whether they ever agreed to be exclusive. The breach is often of an assumed contract, never spelled out.
How affairs begin
An affair is a process, not an event
The most cited framework comes from Allen, Atkins, Baucom, Snyder, Gordon and Glass (2005), who examined infidelity through intrapersonal, interpersonal and contextual factors. They described a time course running through predisposing, approach, precipitating, maintenance, disclosure and response factors.
A useful way to hold this together is a diathesis-stress model: personal vulnerabilities and situational pressures combine to raise the likelihood of an affair. Neither alone tells the whole story.
Who is more vulnerable?
Individual factors
In a randomised trial sample, those who had affairs showed more marital instability, dishonesty, arguments about trust, narcissism and less time with their spouse.
Men who had affairs showed more substance use, were older and were more sexually dissatisfied than women who had affairs.
Low commitment and insecure attachment raise the risk of online infidelity.
Broader correlates include age, gender, religious behaviour, prior divorce, marital satisfaction and education.
Family background
Children who believed their parents had been unfaithful were significantly more likely to cheat in their own adult relationships.
Why people have affairs
The idea that affairs always signal a broken marriage does not hold up. Selterman and colleagues surveyed 562 adults who had been unfaithful and identified eight common motives.
These were: anger, low self-esteem, lack of love, low commitment, need for variety, neglect, sexual desire and situational factors.
Men more often cited sexual desire, variety and situation; women more often cited neglect.
Selterman argues infidelity is not simply a symptom of a damaged relationship — many motives do not reflect relationship quality at all.
Motive shapes the affair
Those who cheated out of lack of love or anger had longer affairs, more likely to end the primary relationship.
Lack of love and neglect predicted greater intimacy with the affair partner, saying “I love you”, dates and public affection; situational motives predicted the opposite.
Situational affairs tended to be shorter and less satisfying, kept secret, with the person staying with their partner.
Not always an unhappy marriage
Glass and Wright found over half of men who had extramarital sex described their marriages as happy or very happy, with the affair purely sexual.
The early stage
In the “approach” phase, a connection with a third person deepens before any line is crossed. The research picture is of escalating opportunity, secrecy and emotional disclosure, rather than a sudden decision. This matters clinically: people often say it “just happened”, but the process usually had identifiable stages.
Secrecy and discovery
Most people kept their affair secret; only a third disclosed it to their partner.
Women were more likely to disclose than men (41% vs 30%).
Only around 1 in 5 broke up as a direct result of the affair, though a further 27% separated afterwards for other reasons.
The impact on the betrayed partner
A trauma response
Infidelity is increasingly understood as a traumatic event. The term “post-infidelity stress disorder” was coined to describe PTSD-type symptoms in betrayed partners.
Typical features include fixation on the infidelity, preoccupation with the affair and avoidance.
Re-experiencing, avoidance, negative mood changes and hyperarousal have been measured using the standard PTSD checklist.
PTS symptoms have been found at relatively high rates even among unmarried young adults, with poorer psychological health overall.
Depression and other mental health problems are also common.
The attachment injury
Johnson and colleagues describe an “attachment injury” as a betrayal or abandonment at a critical moment of need. The event then becomes the yardstick for whether the partner can ever be trusted. Unresolved, it can lock couples into an attack-defend pattern and block repair.
Not every affair is experienced this way — some forms of infidelity become attachment injuries and others do not. Recalling the incident often triggers a traumatic reaction even in therapy.
Immediate reactions
A study of 757 people grouped reactions into 17 factors; the most likely were negative emotions, ending the relationship, keeping physical distance and seeking more information.
The role of others
A meta-analysis of 29 studies (6,510 people) found negative reactions to disclosing trauma were linked to more PTSD symptoms, while general positive support was linked to fewer.
Support mattered most when the betrayal came from a romantic partner.
The impact on the involved partner
The person who had the affair is often overlooked, yet research shows real distress.
A study of recovered couples traced the unfaithful partner’s journey: discovery felt like a “symbolic death”, followed by the weight of guilt and honest self-examination, and finally a re-creation of the self.
When couples remained fixated on the affair’s impact, betrayed partners tended to stay angry and mistrustful while unfaithful partners kept rationalising.
The impact on the affair partner
Research is sparse, but what exists suggests significant suffering.
Analysis of 60 posts in an online support group found affair partners living in the shadow of loss, with strong ambivalence and opposing impulses coexisting.
The impact on children
Children are deeply affected, whatever their age and whether or not the parents separate.
How children find out
Thorson identified five routes: discovery through a third party, from a family member other than the unfaithful parent, from the unfaithful parent, gradual discovery, and explicit discovery.
Emotional consequences
Salih and Chaudry’s study at City, University of London identified recurring themes:
Adultification — children taking on adult roles.
Becoming an emotional carer for a parent.
Unwanted awareness of parental sexuality.
Fear of abandonment and breakdown in their own relationships.
Intergenerational transmission of infidelity.
Younger children may respond unconsciously to parental anxiety or conflict. Adult children are far more likely to recognise the tension and ask directly.
Being caught in the middle
In 215 adult children, the link between feeling caught between parents and lower wellbeing was explained by rumination.
This held whether the parents divorced or stayed together.
Thorson’s interviews with 38 adult children explored coping within families that avoided talking about the affair.
The intergenerational pattern
Across 1,254 participants, parental infidelity was associated with a greater likelihood of offspring cheating.
The odds of infidelity were 2.5 times higher where there had been parental infidelity.
Parental infidelity did not significantly damage offspring’s trust or sense of competence in relationships.
The mechanism appears to be socialisation: parental infidelity conveys memorable messages that cheating is more acceptable, which children absorb.
Weiser stresses this is not destiny — relationship satisfaction and other factors matter greatly.
What helps children
Thorson’s research found that parents who acknowledged the affair and expressed regret — through complete apologies or seeking forgiveness — shaped their children’s ability to forgive.
Discovery method matters: relational outcomes were better when parents disclosed promptly, apologised and gave an account of their behaviour.
How repair happens
Evidence-based couple therapy
The integrative model (Gordon, Baucom and Snyder)
Impact: containing emotional turmoil and destructive interactions before anything else.
Meaning: examining relationship, outside and individual factors to build a formulation of how the affair happened. Understanding is not excusing.
Moving forward: forgiveness, beliefs about it, its consequences and blocks to it, leading to an informed decision — together or apart.
This approach has reduced depression and PTSD symptoms while increasing forgiveness and intimacy.
Emotionally Focused Therapy (Johnson)
The Attachment Injury Resolution Model was developed to address the impasses these injuries cause.
Repair requires the offending partner to be emotionally accessible and responsive to the injured partner’s core emotions and attachment needs.
In a three-year follow-up, improvements in adjustment, trust and forgiveness, and reduced injury severity, were maintained.
What predicts success
Disclosure: couples who disclosed before or during therapy improved more than couples without infidelity.
The involved partner’s conduct: commitment, loyalty, open communication and active engagement predict good outcomes.
Prior relationship quality: a positive view of the relationship before the betrayal helps repair.
Forgiveness and growth
Forgiveness may reduce mental health difficulties by lowering trauma symptoms.
Post-traumatic growth occurs even in couples who stay together, with forgiveness a key predictor.
Therapy, psychoeducation, support and forgiveness all contribute to growth.
Realistic outcomes
Couples with open infidelity are more likely to divorce after therapy (43% vs 23%).
But couples who stayed together showed no difference in satisfaction five years later from couples without infidelity.
Repair for children
Keep children out of the middle: no confidants, messengers or allies.
Acknowledgement and apology from the unfaithful parent support children’s forgiveness.
Silence and topic avoidance do not protect children; honest, age-appropriate acknowledgement appears to.
Limitations of the evidence
Much research is US-based, uses young or student samples, and relies on self-report.
Children’s outcomes come mostly from adults recalling childhood.
Affair partners and involved partners are under-researched.
Most findings are correlational, not causal.
Closing thought
An affair is rarely a single moment of madness; it unfolds through identifiable stages, driven by a mix of personal, relational and situational factors. Its impact is traumatic for the betrayed partner, painful for the involved partner and affair partner, and potentially long-lasting for children. Yet the research is clear that repair is possible. Honesty, accountability, emotional responsiveness and structured help give couples — and families — a real route through.
References (peer-reviewed)
Allen ES et al. (2005) Clin Psychol Sci Pract 12:101–130
Atkins DC, Baucom DH, Jacobson NS (2001) J Fam Psychol 15(4):735–749
Atkins DC et al. (2005) J Consult Clin Psychol 73(1):144–150
Glass SP, Wright TL (1985) Sex Roles 12:1101–1120
Gordon KC, Baucom DH, Snyder DK (2004) J Marital Fam Ther 30(2):213–231
Johnson SM, Makinen JA, Millikin JW (2001) J Marital Fam Ther 27(2):145–155
Makinen JA, Johnson SM (2006) J Consult Clin Psychol 74(6):1055–1064; three-year follow-up (2010) J Couple Relat Ther 9(1):31–47
Labrecque LT, Whisman MA (2017) J Fam Psychol
Marín RA, Christensen A, Atkins DC (2014) Couple Fam Psychol 3:1–12
Mitchell EA et al. (2021) J Marital Fam Ther 48(2):447–463
Salih L, Chaudry S. Exploring the lived experience of parental infidelity
Selterman D, Garcia JR, Tsapelas I (2017) J Sex Res; (2020) J Sex Marital Ther
Thorson AR (2013) Qual Commun Res 2(1):61–80; (2017) J Divorce Remarriage 58(3):175–193; (2019) J Soc Pers Relat 36(9):2759–2780
Weiser DA, Weigel DJ (2017) Personal Relationships 24:933–952
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