Our relationship status may affect who and what we find attractive, scientists have said. When they are in a relationship, people are more likely to be drawn to faces that resemble their own, while singles are more likely to find that opposites attract.

The choice of a mating partner depends not only on characteristics of the potential partner, but also on the degree to which these characteristics complement the choosing individual. In animals, scientists often observe a preference for dissimilarity when choosing a mate and this is often explained as an evolutionary adaption to increase the chance of having genetically diverse offspring.

This study, published in Frontiers in Psychology, shows this is not so evident in humans, as in certain contexts, self-resemblance can be favoured. The scientists suggest this is more the case when people already have a partner.

Rating faces

About 100 students participated in the experiments conducted by scientists from Charles University in the Czech Republic.

They were asked about their relationship status and then showed photographs of faces that had been digitally manipulated to be either more or less similar to the student's face. They were presented with both same-sex and opposite-sex faces. They were asked which faces they found most 'sexy' or attractive and then to rate their preferences.

The scientists found out that single participants rated dissimilar faces as more attractive and sexy than self-resembling faces. The opposite trend was observed for those in a relationship.

"Our interpretation is that attractiveness perception mechanisms that give us a preference for a genetically suitable partner may be suppressed during romantic relationships," explains lead author Dr Jitka 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 had previously been done about how our perceptions of others change when we enter a relationship. These findings could be the first step towards understanding such processes.