Researchers have debated for years whether men or women are likelier to engage in “mate poaching.” Some surveys indicated that men had a stronger tendency to go after other people’s partners, but was that just because men were more likely to admit engaging in this behavior? Now there’s experimental evidence that single women are particularly drawn to other people’s partners, according to a report in the Journal of Experimental Social Psychology by two social psychologists, Melissa Burkley and Jessica Parker of Oklahoma State University.

Noting that single women often complain that “all the good men are taken,” the psychologists wondered if “this perception is really based on the fact that taken men are perceived as good.” To investigate, the researchers quizzed male and female undergraduates — some involved in romantic relationships, some unattached — about their ideal romantic partner.

Next, each of the experimental subjects was told that he or she had been matched by a computer with a like-minded partner, and each was shown a photo of an attractive person of the opposite sex. (All the women saw the same photo, as did all the men.) Half of the subjects were told that their match was already romantically involved with someone else, while the other half were told that their match was unattached. Then the subjects were all asked how interested they were in their match.

To the men in the experiment, and to the women who were already in relationships, it didn’t make a significant difference whether their match was single or attached. But single women showed a distinct preference for mate poaching. When the man was described as unattached, 59 percent of the single women were interested in pursuing him. When that same man was described as being in a committed relationship, 90 percent were interested. The researchers write:

According to a recent poll, most women who engage in mate poaching do not think the attached status of the target played a role in their poaching decision, but our study shows this belief to be false. Single women in this study were significantly more interested in the target when he was attached. This may be because an attached man has demonstrated his ability to commit and in some ways his qualities have already been ‘‘pre-screened” by another woman.

Well, that makes sense. But I asked Dr. Burkley, a professor of social psychology at Oklahoma State, if the correlation could also be due to another factor at work in some women: fear of intimacy. Could their interest in unavailable guys be what was keeping them single in the first place?

Maybe, Dr. Burkley replied. “There are many possible explanations for our results,” she told me, “and future research needs to identify exactly why single women prefer taken men. Our lab is currently conducting studies to try and tease apart the different potential explanations for our findings, but your explanation seems quite plausible.”

What’s your explanation? And do you have any data — anecdotal or otherwise — to offer?