Most people — 72% or nearly 3 out of 4 of Americans — believe that society is better off when couples are sexually faithful to each other. Even among people who admit they are not always faithful to their partners, 47% still agree that society is better off when others are.
Despite our preferences, infidelity occurs. Though it’s maddeningly difficult to determine what the actual rate of infidelity is. If we limit ourselves to married couples, the rate of infidelity, whether a one-time or longstanding affair, is somewhere between 15% and 30%. In my Born to Marry study, I only asked whether people had cheated on their current spouse, ignoring prior marriages if there were any — the number who admitted to cheating was 16%, on the lower end of where other studies put the range. Of course, some of the currently faithful may yet become unfaithful so the numbers are a moving target. But the fact to remember from all this is that even though most of us value sexual fidelity, somewhere around a fourth of us will not be faithful over the span of our marriages.
There is good news in this. First, it means that unlike the doom-and-gloom thoughts people have about divorce (“half of all marriages end in divorce,” which is not true and becoming less so each year as divorce rates fall), it means that on a purely random level, most marriages will not experience fidelity.
The real nugget of insight in there is the fact that infidelity is decidedly not random. People make choices — not just to commit adultery but to put themselves in situations where adultery is possible. Marriage counselors have ample advice for how to make choices that will avoid infidelity. Happily, the same advice for drawing you together will likely keep others out.
The truth is that our bodies partake of the same animal nature that causes most animals not to be monogamous for life. Seen this way, it’s somewhat surprising that most marriages do not cave to infidelity. Some might say that admitting our animal nature is a handy excuse for giving in to temptation, but I see it as precisely the opposite. Understanding that our bodies are animal can help us overcome the sometimes-disloyal thoughts we might have. If a thought of another distracts us from our pair bond, instead of believing that we are falling in love with another person, a near-mystical state that might be hard to resist, we can choose to see that those feelings of attraction are mere biological signals.
Managing the body is not just about managing moments of response, moments of decision. The body also has a memory we can choose to populate as we wish and which guides our future thoughts and actions. As anyone who has tried to change a physical habit knows — switching from skiing to snowboarding, for example — your mind and body develop muscle memory and preferences for behaviors you have previously mastered.
Which leads to my point: One such behavior some have mastered is the ability to meet and have a sexual relationship with someone they are not emotionally invested in or socially committed to. Whether a one-night stand or a three-week fling, such short-term liaisons are precisely the kind of thing that some of us would be awful at not because we don’t have the same tempting desires that others do but because we have no practice in doing them. I would not know the first thing to do in a bar to signal to someone that I’m interested in hooking up. I’ve never done it! This is great for my marriage.
Is there evidence that people who have more practice with what researchers call short-term mating strategies are more likely to cheat? Yes, there is. As I wrote for the Institute for Family Studies (IFS) in late 2019, the Born to Marry study reveals that people who have had more sexual partners in their life have developed more skill at having low-emotion, low-commitment sexual encounters. This, in turn, makes them less likely to commit to being faithful to their current sexual partner. As I wrote in The Road to Infidelity Passes Through Multiple Sexual Partners:
…infidelity is also often the fruit of a lifelong approach to mating that involves seeking and practicing short-term mating encounters that encourage sexual variety at all stages and into marriage.
How do you get to infidelity? Practice, practice, practice.
There are more questions to ask. For example, is it possible that the people more likely to practice hook-up culture are already different from people who do not? This would make them more likely to continue to engage in short-term mating behaviors even after marriage. This is not only possible, it’s probable. Which is why the Born to Marry project is so helpful. If someone looks at the variety of relationships available to them and concludes that they will be more satisfied with short-term mating experiences, then they are probably low on the Born to Marry scale (did you take the test yet?). That would be important for them to know. It would also be important for someone considering a relationship with that individual to know as well. It definitely suggests that a potential partner who thinks they have found a previously promiscuous mate who through their love will somehow longer want sexual variety will be fighting an uphill battle. Not unwinnable, but certainly much harder.
You fit somewhere in and among this mix of inborn urges, acquired habits, and socially motivated behaviors. You have choices to make: If you are Born to Marry, your best path forward is clear — aim for long-term, exclusive relationships that lead to faithful marriage. That will make you happiest, most satisfied with life, all of which I can verify with statistics. And if it leads to being a grandparent some day, I can verify by personal experience that your cup of joy will then be overflowing.