By: Whitney E. Petit

People are social creatures who are quick to form new relationships and reluctant to dissolve existing ones.  In fact, theorists propose that people have a psychological need to form and maintain close relationships.  Romantic relationships appear to be particularly important, having unique and powerful effects on mental and physical well-being.  Although they are one of many sources of joy in people’s lives, romantic relationships are rarely impervious to acts of infidelity.  In fact, as many as 60 percent of men and 50 percent of women have sex with somebody other than their spouse while married, and other studies reveal that many, if not most, college students have engaged in some form of infidelity.  Almost universally, though, people disapprove of marital infidelity with dating infidelity being slightly less unacceptable. 
 
Despite their importance, maintaining romantic relationships is obviously a difficult task.  Unfortunately, couples face many obstacles and challenges that threaten their commitment and rob them of their “happily ever after.”  According to the U.S. Census Bureau, one out of every five marriages in the United States ends in divorce within five years of tying the knot.  Not surprisingly, people want to guard against divorce and break-ups, so they engage in strategies to protect their relationship.
 
Theorists suggest that we judge relationships based on our perceptions of the balance between what we put into the relationship and what we think we deserve from the relationship, as well as the perceived chances of having a better relationship with someone else (an alternative partner).  As more attractive alternative partners become available, the probability of relationship dissolution increases.  That is, people become less committed to their relationship to the extent that there are other attractive possibilities.  It follows, then, that one could protect a current relationship by devaluing the attractiveness of alternative partners.
 
Existing research on this topic collectively suggests that people in committed relationships devalue the attractiveness of other potential partners, which serves as a line of defense in relationship-maintenance.  Two hypotheses account for the devaluation of alternative partners; one that emphasizes a conscious process and one that emphasizes an unconscious process.  According to the first explanation, relationship commitment motivates one to consciously override or suppress initial, automatic perceptions of attraction to another person.  In other words, people convince themselves that others are less attractive.  In contrast, the second explanation suggests that relationship commitment inhibits initial perceptions of attraction to another person directly.  Basically, other people simply appear less attractive.
 
To date, studies have not tested whether individuals in a relationship compared to those not in a relationship differ in their involuntary, automatic perceptions of attraction.  Our research provided the first direct test of the two competing hypotheses by comparing an automatic measure of attraction, in this case pupil dilation, to people’s self-reported attraction toward an alternative partner.  
 
We found that people rate alternative partners as significantly less attractive when they are in a relationship compared to when they are not in a relationship, which is consistent with previous findings.  Interestingly, however, when presented with an alternative partner people’s pupils dilate almost exactly the same amount regardless of relationship status.  These findings support the notion that individuals in a relationship actively devalue alternatives as part of a relationship maintenance mechanism.  In other words, both individuals in a relationship and those not in a relationship initially and automatically perceive an alternative partner as equally attractive.  Those in a relationship, though, suppress or deliberately recalibrate their perceptions of attractiveness and believe that the alternative partner is in fact not as attractive as their physiological reaction proves. 
 
How people guard their relationship from threats of alternative others is a critical research question as the percentage of individuals who commit infidelity remains disturbingly high. Our research suggests that we all come with a built in mechanism to devalue the attractiveness of alternative partners, which activates when we are in a relationship.  Clearly, the temptation of alternative partners can represent a serious and pervasive threat to a couple's "happily ever after.”  Nevertheless, one way people in a relationship guard against this threat is by convincing themselves that alternative partners are less attractive.