Men and women have proven time and again that it is possible to have platonic relationships, but now a study shows that while men might know that they're "strictly friends", they can't help but want more from their female friends.

Not only do men typically have more carnal desire for their female friends, they're also more likely to overestimate just how much their female friends want them. Men aren't completely delusional, however, viewing this sexual attraction as a burden rather than a benefit.

April Bleske-Rechek psychologist at the University of Wisconsin, whose study this is, says that it's clear that men and women are keen to have platonic relationships with the opposite sex, but that it's not as easy as that.

"The data I've been collecting suggests that attractions can get in the way," she told LiveScience.

Friends without benefits goes against our evolutionary grain, she observes, saying that platonic friendships offer up an interesting dynamic in evolutionary theory of reproduction.

Bleske-Rechek and her team studied how friends of the opposite sex who were also heterosexual dealt with the issue of sexual attraction.

The team had people from 88 friendships of this kind fill out questionnaires, making sure that both parties agreed they were in fact friends by asking the pair to come in to fill in the questionnaires under observation. However, the friends filled out the questionnaires separately and were asked to keep their answers confidential.

The results were perhaps predictable with men showing far higher levels of attraction to their female friends than the other way around and were also more likely to overestimate how much their female friends reciprocated these feelings of attraction.

This overestimation by men is not new. "Men over-infer women's sexual interest in a variety of contexts, and I definitely see that extending into the domain of cross-sex friendships as well," Bleske-Rechek explained.

Those male friends who were romantically involved with another women were as likely to say they found their female friends attractive as the single men, and as likely to say they'd date her if they got a chance.

The same level of attraction applied to women in relationships, but far more single and romantically-involved women said they'd avoid dating their male friends.

A further questionnaire was sent to 322 adults ranging in age from 27 to 55, finding that while platonic friendship is seen as hugely beneficial, once again more women than men rate sexual attraction within the friendship as a negative thing.

Bleske-Rechek says that the findings shouldn't be seen as proving that platonic friendships don't work, but rather that our evolutionary history offers a few hurdles to overcome in this kind of friendship.

"It's very likely that the modern environment has changed so quickly that we've got these novel opportunities to engage in a variety of types of relationship with the opposite sex that we probably didn't, historically."

"It's going to take us a while to adjust."