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This Magic Formula Makes Couples More Likely to Be Faithful

How self-expansion increases relational quality and reduces infidelity.

Source: Stockfour/Shutterstock

Have you ever seen an older couple out together, talking and laughing as if they were on a first date? If they are engaging in stimulating activity that they both genuinely enjoy, they probably feel like they are. Research shows that self-expansion within existing relationships improves relational quality and reduces the chances of infidelity.

Self-Expansion and Relational Satisfaction

A study by Laura E. VanderDrift et al. (2011) examined the link between self-expansion and attention to relational alternatives.[i] They found that romantic partners who report lower self-expansion within current relationships, defined as “the fundamental human need to expand one’s sense of self,” demonstrated greater interest in relational alternatives. This is what we might expect, because individuals low in self-expansion seek opportunities to meet this need, and one way is to meet and interact with new people.

The authors begin by discussing the concept of self-expansion. They note that relevant literature highlights two types of experiences associated with self-expansion: “engaging in novel and arousing activities and including another person in one's self-concept.” They state that the combination of these two experiences may actually explain the process of building romantic relationships, because falling in love is an arousing process containing an amount of novelty, and relational maintenance involves including a partner within one's sense of self.

The Benefit of Positive Bias

VanderDrift et al. explain that many couples experience self-expansion within existing relationships. This is the ideal situation and triggers the operation of two distinct positive biases.

The first is a motivational bias, where partners devalue the quality of potential romantic alternatives in order to maintain cognitive consistency. In other words, they view romantic alternatives as less attractive, both physically and emotionally, than they objectively are.

The second is a perceptual bias, where individuals perceive alternatives as low quality or not at all — meaning they simply fail to notice alternatives to begin with.

Both of these biases contribute to the stability of the current relationship through providing an inaccurate view of alternatives.

The researchers found that lack of self-expansion within a current relationship can cause these two biases to fail, which in their study led participants to self-report an increased susceptibility to infidelity.

The good news is that there are a variety of ways that couples can reduce the temptation to explore relational alternatives by increasing opportunities for self-expansion within existing relationships. One way to do this is through engaging in mutually enjoyable activities.

Playing Together, Staying Together

Spending time having fun together strengthens romance. Many couples hit it off in the first place in part because they share common interests. From hiking to hunting, cooking to camping, happy couples engage in mutually enjoyable activities.

Even couples who are celebrating a 30-year anniversary can benefit from considering the things that drew them together in the first place, and what types of activities they enjoyed. Barring physical limitations, even partners in long-term relationships can rekindle the excitement of shared adventure.

What kinds of activities do the trick? Thankfully, research shows partners do not have to strap on parachutes or bungee cords to acquire the level of arousal that will spice up an established relationship. It can be as easy as asking your partner to dance.

Mutually Enjoyable Activities Are Better Together

In a study entitled “Lovers With Happy Feet” (2012), Nathalie C. Ricard et al. studied the relational and activity satisfaction of romantic partners who practiced ballroom dancing together, within the context of self-determination theory.[ii]

They studied participants’ self-reported motivation and dyadic adjustment for their romantic relationships, and while dancing. They found that couple functioning impacts the functioning and satisfaction of joint activities — which can in turn improve relational quality.

Ricard et al. note that their results are consistent with prior research finding that couples can improve relational satisfaction through engaging in activities together that they both enjoy. On the other hand, they note that couples who engage in activity together because they feel pressured to do so are less likely to derive a relational benefit than those who are motivated by the pursuit of pleasure (self-determined motivation).

Compatibility Breeds Contentment

This research supports the notion that strong relationships begin with partners who are genuinely compatible. Feigning interests to appeal to a partner (professing a passion for football while not knowing who is in the Super Bowl, or roughing it on a campground when you would rather be at the local Marriott) will not contribute to relational satisfaction in the long run.

Couples who are motivated to maintain a positive relationship can do so through participating in mutually enjoyable activities, because self-enhancement breeds relational satisfaction. So whether you reach for dancing shoes, hiking boots, or house slippers, choose an activity that genuinely appeals to both of you. Then enjoy it together.


[i]Laura E. VanderDrift, Gary W., Lewandowski Jr., and Christopher R. Agnew, “Reduced self-expansion in current romance and interest in relationship alternatives,” Journal of Social and Personal Relationships 28, no 3, 2011, 356-373.

[ii]Nathalie C. Ricard, Simon G. Beaudry, and Luc G. Pelletier, ”Lovers With Happy Feet: The Interdependence of Relationship and Activity Factors for Individuals Dancing With a Romantic Partner,” Journal of Applied Social Psychology 42, no. 4, 2012, 939-963.