WASHINGTON, Feb. 12 (Xinhua) -- If a married person tends to look longer than average at an attractive individual who could be considered a romantic option, he or she is more likely to be unfaithful in marriage, according to a research published Monday in the Journal of Personality and Social Psychology.

The study, by a research team in the Florida State University, followed 233 newly-wedded couples for up to 3 1/2 years and documented intimate details of their relationships, including marital satisfaction, long-term commitment, whether they had engaged in infidelity and if they were still together.

The team tested the newlyweds two psychological processes that everyone shares in varying degree. The first is the ability to direct attention away from an attractive person who could be considered a romantic option. The second is a tendency to mentally downgrade the attractiveness of another person, even if he or she is especially good looking.

Researchers have discovered that participants who quickly disengaged their attention from an attractive person were less likely to engage in infidelity.

The time of that response was notable: Individuals who looked away in as little as a few hundred milliseconds faster than average were nearly 50 percent less likely to have sex outside marriage.

Conversely, partners who took significantly longer to look away from romantic alternatives had a higher risk of infidelity, and their marriages were more likely to fail.

The tendency to devalue the attractiveness of potential romantic partners also lowered the risk of infidelity and raised the likelihood of maintaining the relationship. Faithful people evaluated romantic alternatives much more negatively.

"People are not necessarily aware of what they're doing or why they're doing it," said Jim McNulty, the lead author of the study. "These processes are largely spontaneous and effortless, and they may be somewhat shaped by biology and/or early childhood experiences."