If you're preoccupied with infidelity, new research may help set your mind at ease.

Two longitudinal studies have revealed some of the factors that correlate with cheating - and, on the flipside, with fidelity, at least in the short term.

Over 3.5 years, researchers at Florida State University followed 233 newly married couples across two longitudinal studies, comparing certain behavioural tendencies to the couple's fidelity over time, and whether they were still together.

The team focussed on two psychological processes we may engage when assessing potential romantic partners: 'attentional disengagement' and 'evaluative devaluation'.

Attentional disengagement happens when when you're able to tear your attention away from something - in the case of the research, the participants were shown pictures of attractive people who could be considered a romantic option.

Meanwhile evaluative devaluation is mentally "downgrading" a potential romantic partner, even if it is one you'd consider especially attractive. 

Both studies assessed attention disengagement, and the second one additionally looked at evaluative devaluation as well. The researchers checked in on the couples' infidelity and relationship status multiple times over the duration of the studies.

The team, led by psychology professor Jim McNulty, showed both members of the couple photographs of very attractive men and women, as well as photographs of average-looking men and women (although it's not clear by which metric attractiveness was gauged).

The team found that those partners who disengaged their attention from attractive photos more quickly than average were nearly 50 percent less likely to cheat on their spouses.

Those who looked at attractive photos for longer than average were much more likely to cheat.

And those people who mentally downgraded attractive people, opting to find them less attractive, were also less likely to cheat on their spouses.

It's also worth noting that none of these behaviours are conscious - but if you're aware of them, you can nip your roving eye in the bud.

"People are not necessarily aware of what they're doing or why they're doing it," McNulty said.

"These processes are largely spontaneous and effortless, and they may be somewhat shaped by biology and/or early childhood experiences."

Although not the focus of the study, the results also identified other factors that correlated strongly with the likelihood of infidelity.

Younger people, those less satisfied with their relationships, and those with a satisfactory sex life were more likely to cheat on the partners. The latter is a surprising result, but the researchers hypothesised it could be because those people had a more positive attitude towards sex.

The woman's attractiveness in a heterosexual couple also played a role. Less attractive women were more likely to cheat themselves - and also to be cheated on by their husbands. However, the man's attractiveness didn't seem to make a difference to the likelihood of infidelity.

Finally, sexual history also played a role. Men with a larger number of short-term partners before marriage were more likely to cheat, whereas women with a smaller number of partners before marriage were more likely to cheat.

While the team only looked at a fairly small pool of newlyweds, insights from these results could potentially help stave off infidelity before it even occurs, the researchers said.

"These findings suggest a role for basic psychological processes in predicting infidelity, highlight the critical role of automatic processes in relationship functioning, and suggest novel ways to promote relationship success," they wrote in their paper.

The research has been published in the Journal of Personality and Social Psychology.