By Alex Fradera

Half of us have been unfaithful in our lifetime, and one in five people within their current relationship. As sexual infidelity is the primary cause of divorce and one of the hardest issues to address in couples therapy, identifying any useful defences could make a huge difference to people’s happiness. In a recent paper in Personal Relationships Brenda Lee and Lucia O’Sullivan from the University of New Brunswick investigated what strategies people in relationships use to reduce the chances they will cheat – so-called “monogomy maintainance strategies” – and looked into whether or not they are actually effective.

The pair surveyed 362 heterosexual adults aged 19-63 online about how they’d tried to resist temptation when they had been in a relationship and had felt a strong attraction to someone else. Their answers suggested there are three main types of monogomy maintainance strategy: “relationship enhancement”, used by three-quarters of participants, included things like taking a partner out on a date, making an extra effort with their appearance around their partner, or engaging in sexual acts with them; “proactive avoidance” was similarly common, and involved maintaining distance from the temptation, both physically, and also in terms of avoiding getting close in conversation; and finally “derogation of the temptation”, which was slightly less frequent, and involved applying negativity towards the relationship threat, and guilt towards the self, in an attempt to pour cold water on the prospect.

Lee and O’Sullivan’s findings suggest these strategies are largely ineffective. Participants reported flirting less when they applied the final, negative kind of strategy. But none of the strategies had an effect on more consequential outcomes: romantic infidelity, sexual infidelity, and whether the current relationship survived. This pattern was borne out in a followup study with more participants that asked them how they were dealing with a threat to a current relationship. So as informative as this research is, it paints a gloomy picture: we may call upon these techniques, but they don’t appear to make much difference in staving off temptation.

Thankfully, there is some optimism to be found in another recent study on the same topic, published in the Journal of Personality and Social Psychology. This paper zoomed in on moment-to-moment attentional responses, and these seemed genuinely predictive of success in avoiding infidelity.

Across two experiments, the researchers, led by James McNulty at Florida State University, asked members of 233 newly married couples whether they had ever engaged in infidelity in the relationship – 37 confessed.

The same participants also completed a task where they had to disengage from images of attractive opposite-sex faces in order to respond quickly to stimuli flashed up elsewhere on a computer screen. McNulty and his team explain how this automatic disengagement from attractive prospects is plausibly an aid to monogamy maintenance, and the data bore this out: participants who were substantially better at disengaging from the alluring pictures were half as likely to have been unfaithful.

Another component of the experiment involved rating the physical attractiveness of the images involved in the task. All the participants considered the images as somewhat less attractive than did a separate group of single participants, reflecting a well-established tendency for people in relationships to devalue the attractiveness of others. McNulty’s team predicted that the married participants who engaged in more of this devaluing of temptation would be more likely to be faithful, and again the results confirmed this.

Why is it that these attentional processes were associated with lower infidelity, yet Lee and O’Sullivan’s monogamy maintaining strategies (including the similar-sounding derogating and downplaying of the relationship threat) were ineffective? Perhaps it has to do with the attentional process (McNulty’s team call them “psychological biases”) being automatic, while the monogamy maintaining strategies are more deliberate and perhaps, sometimes, too late. After all, if I meet someone captivating at a party, I might get home and decide to tell myself they aren’t so great (ticking the box for that strategy). But if I’m unpracticed, I may not persuade myself. In fact I may wrestle with myself and end up ruminating on that person all the more.

Building the automatic, habitual protective processes uncovered by McNulty’s team arguably takes practice. So if we want to maintain our relationships by staying monogamous, sacrifices are needed ahead of time. The well-trained mind can dial down the titillation of temptation to a background hum: it won’t get to enjoy the occasional harmless little interludes, but nor will it be carried away by the crescendo.

—Ain’t misbehavin? Monogamy maintenance strategies in heterosexual romantic relationships

—Attentional and evaluative biases help people maintain relationships by avoiding infidelity

Alex Fradera (@alexfradera) is Staff Writer at BPS Research Digest