If we are in a relationship we are more likely to be attracted to faces resembling our own, but for single people, opposites attract.

Relationship status affects who and what we find attractive, found a study published in Frontiers in Psychology.

Dr Jitka Lindová of Charles University in the Czech Republic and her team showed a series of photographs of faces to university students and asked them to rate their attractiveness. The photographs were digitally manipulated so that the resemblance to the student was modified.

Images were of an individual of the opposite sex, whose face had been manipulated to look either more or less similar to the student. They were also presented with images of a same-sex individual manipulated in the same way.

"We found that single participants, those not in relationships, rate dissimilar faces as more attractive and sexy than self-resembling faces;" stated Lindová.

This was observed when participants rated both same-sex and opposite-sex faces.

"For the first time, we have observed how our partnership status affects who we find attractive;" she added.

"Our interpretation is that attractiveness perception mechanisms that give us a preference for a genetically suitable partner may be suppressed during romantic relationships," explained Lindová; "This might be a relationship maintenance strategy to prevent us from finding alternatives to our own partner, or perhaps self-resemblance becomes more important in terms of the social support we expect receive from relatives, which are known as kinship cues."

Little research has been carried out about how our perceptions change when we enter a relationship. These findings have important sociological and biological implications that require further study.

In addition, Lindová pointed out that this work may be of interest to the applied psychological sciences.

"For example, as those not in a relationship were not influenced by kinship cues and our findings might help to explain social phenomena such as parent and adolescent disaffection;" she said.