As much as we may all wish that it didn’t happen, on any given day someone in a romantic relationship or marriage is cheating on their partner. We know that this is a common phenomenon for both unmarried and married couples.
But is there any merit to the old saying “once a cheater, always a cheater?” Is this really the case in real-life couples, not just on TV and in movies?
Based on what we know from recent social science research of mixed-gender (heterosexual) couples, the short answer is:
Yes, it’s more likely. But it’s not necessarily true.
This is such a simple question with a clear cut answer. But we have learned a lot. Keep reading!
What Puts People at Risk for Cheating?
First, let’s start with a quick look at some of the factors that have been linked to cheating.
To be clear, these are factors that have been found to be correlated to (associated with) cheating. These are NOT factors that have been shown to CAUSE a person to cheat.
If you went to college, remember from Research Methods 101: Correlation does not equal causation.
Ultimately, a person can have all of these factors but this doesn’t mean we can predict with certainty that they’ll actually cheat on their partner. In the end, the decision to cheat is a personal one and one that even researchers and clinicians will likely never fully understand, let alone predict.
Side note here but important:
Because words like “adultery,” “infidelity,” and “extramarital relationships” are generally used to refer to being unfaithful to one’s spouse (in other words, cheating while married), on occasion I’ll use the term “extradyadic relationship” here, as many social science researchers do.
Yes, it’s a mouthful! But this term is inclusive of cheating that also happens in non-marital relationships.
Now, on to the more important stuff…
Some of the individual factors that put people at risk for having extradyadic relationships include:
• Low commitment
• Declining satisfaction with one’s relationship, or with the sexual part of one’s relationship
• Personality traits & attachment styles
• Permissive attitudes (e.g., about sex, about cheating)
• Individual patterns around sex (e.g., how inhibited one is about sex, what sexually excites a person)
• Being in a social environment that is approving or permissive of extradyadic relationships (e.g., within one’s cultural group or family)
And some of the demographic factors that put people at risk for having extradyadic relationships include:
• Gender – while there’s evidence that women cheat more often than previously thought, men are still more likely to engage in extradyadic relationships (though this difference may be decreasing in younger generations)
• Race – with reportedly higher rates among men in Black and African-American populations
• Socioeconomic status – with mixed findings on whether higher education, income, and employment is consistently linked to higher engagement in extradyadic relationships
Does this mean that if you’re a Black, highly-educated, high-income earning man who grew up in a family with lots of cheating among the adults that you yourself will end up cheating? No. Absolutely not!
Again, these factors have been shown to increase the risk but are not causal or predictive by any means.
Does Cheating Once Mean You (or Your Partner) Will Do It Again?
A 2017 study by some of the top relationship researchers in the field examined nearly 500 people over a 5 year period to see if past infidelity in prior relationships put them at risk for “serial infidelity, ” that is, cheating in later relationships.
All study participants were unmarried adults between ages 18-35 who were all in at least 2 romantic relationships over the study period.
For the study, they defined infidelity as “extra-dyadic sexual involvement” (or ESI for short) which was measured by “whether a person in a romantic relationship has had sexual relations with someone other than their relationship partner.”
The overall rates of ESI found among study participants were:
- 44% reported engaging in cheating themselves (during one or all of the relationships included in the study period)
- 30% reported having at least 1 partner who they knew cheated
- 18% reported that they suspected a partner of cheating
The researchers cautioned that these rates are high because ESI tends to be more common in unmarried couples.
As far as serial cheating goes, they summarized their findings as follows:
Results from this study indicated that people who engaged in infidelity themselves, knew about a partner’s infidelity, or suspected a partner of infidelity had a higher risk of having those same infidelity experiences again in their next romantic relationships.
So what specifically did they find? Let’s look at each of their 3 main research questions one by one…
Question 1: If you yourself cheated in a past relationship, are you more likely to cheat in future relationships?
Although MOST people who cheated in the past or had partners who cheated in the past didn’t have repeat experiences, this study found that for those who did see the history repeat itself the odds were powerful. The likelihood for cheating in future relationships is about 3 times as much if you’ve cheated in past relationships. Wow!
Question 2: If you were cheated on by a past partner, are you more likely to be cheated on in future relationships?
Again, most people did not see history repeat itself. But for those who did, having a past partner who cheated (or who you suspect cheated) increased the likelihood by 2-4 times as much that a future partner would engage in ESI. Again, wow!
Question 3: If you yourself cheated in a past relationship, are you more likely to suspect your future partners of cheating on you?
There was no evidence to support this being true.
Some people believe that if you suspect your partner has cheated it likely means you yourself have cheated. The theory here being that if you accuse your partner of cheating it’s just a means of deflecting attention from your own unfaithfulness. However, this study findings don’t support this notion.
Interestingly though, they did find that suspecting a past partner of cheating made it more likely that you’ll go on to suspect a future partner. This could be due to generally being a distrusting or jealous person but there’s no way to tell from this study.
There’s also no way to tell if those who had suspicions were actually right that their past or current parents had engaged in ESI.
What Motivates “Serial” Cheating?
There are a couple of big theories that have been explored in relationship research to help explain why someone may cheat in more than one relationship.
One theory relates to “alternative partners.” Specifically, the availability and quality of such alternatives to one’s current partner.
The basic idea here is that if you’ve cheated in before, you know firsthand that there are other desirable alternatives available to you. And, if you believe that these alternatives will continue to be available to you, you may have an even higher chance of exploring these options in future relationships.
In other words, one taste of “the alternatives” may create even more of an appetite going forward. Perhaps us humans aren’t as sophisticated as we’d like to believe.
Another theory relates to attitudes about cheating.
According to this theory, even though cheating is seen as socially unacceptable (at least in many Western cultures), if you have more permissive attitudes about cheating you’re more likely to do it regardless of what others think.
On top of this, once you’ve cheated one time – your actions may create even more of an approving attitude toward cheating (because after all, most of us don’t like to look down on our own behavior) which then makes future cheating even more likely.
How Therapy Can Help
Basic Education & Prevention
If you’re worried about cheating or repeated cheating affecting your relationship, couples therapy can help. As an expert, I can give you and your partner basic relationship education that can help.
For example, learning about the normal phases of relationships and common challenges such as declines in sexual satisfaction after marriage is a key way to temper your expectations. Having realistic relationship expectations can help you both prevent the common mistake of comparing alternative partners to one’s current partner.
This is often like comparing apples and oranges, except you’ve never had to pick up the orange’s dirty laundry off the floor.
Basic relationship education can also prevent worry that something is “wrong” with the relationship when common issues come up.
Couples therapy can also give you both the chance to dig deeper into each of your possible risk factors that may make cheating more likely to happen. For example, examining family attitudes about sex and cheating in a guided way can often unlock hidden risks that you may not have seen before.
A huge benefit of high-quality couples therapy is having the change to identify and disrupt negative relationship patterns before they have the chance to cause damage.
For example, if you (or your partner) tend to find yourselves in relationships in which your partner betrays you, there may be underlying issues there they need to be addressed so this pattern doesn’t repeat again.
On the other hand, if you find that you (or your partner) have a pattern of being unfaithful, therapy can give you an honest look at this pattern as well and give you the tools to disrupt and alter it for the future.
Agreement on What’s Ok & What’s Not Ok
It may sound silly or basic, but sometimes couples run into trouble with cheating and then (and only then) realize they don’t agree on what behavior is acceptable in their relationship.
What you may think of as obvious and black-and-white, your partner may think of as… well, it’s complicated.
The researchers of the focus study here point out that “reaching a mutual definition of relationship fidelity couple be beneficial for couples who are at risk due to past experiences or other risk factors.”
Over the years, here are some of the questions I’ve seen couples ask themselves around fidelity:
- Does a texting relationship with another person count as cheating?
- Does watching porn count as cheating?
- Does a one-time kiss with another person need to be treated the same as having sex with someone?
- Is having lunch with an attractive co-worker constitute a betrayal? Could such an act lead to cheating down the road?
- Is having an emotional relationship with an outside person more of a betrayal than a sexual relationship?
- If cheating happens but is never discovered, does it need to be divulged or would you rather not know? Do you two agree on this?
You might take for granted that you and partner would answer these questions the same way. But sadly, many couples don’t realize until after something hurtful has happened that they don’t actually agree on what behavior is ok versus not ok when it comes to outside relationships.
Whether cheating has already happened or not, couples therapy can help create a healthier relationship going forward by guiding you and your partner toward a mutual understanding of the boundaries of your relationship so that future betrayals may be prevented.