Wardrobe malfunction – three failed attempts to replicate the finding that red increases attractiveness

It's one of the simplest, most evidence-backed pieces of advice you can give to someone who's looking to attract a partner – wear red. Many studies, most of them involving men rating women's appearance, have shown that wearing red clothing increases attractiveness and sex appeal. The reasons are thought to be traceable to our evolutionary past – red displays in the animal kingdom also often indicate sexual interest and availability – complemented by the cultural connotations of red with passion and sex.

But nothing, it seems, is straightforward in psychology any more. A team of Dutch and British researchers has just published three attempts to replicate the red effect in the open-access journal Evolutionary Psychology, including testing whether the effect is more pronounced in a short-term mating context, which would be consistent with the idea that red signals sexual availability. However, not only did the research not uncover an effect of mating context, all three experiments also failed to demonstrate any effect of red on attractiveness whatsoever. 

The simple picture that red increases attractiveness, especially in the eyes of men viewing women, had already been muddied by a large study published earlier this year that tried to extend the red effect to the context of waitress tipping, but which found, contrary to expectations, that men gave smaller tips to female servers wearing red. Also other recent papers found the red-attractiveness effect when red was compared with some colours but not others.

For the new research, Leonard Peperkoorn and his colleagues began by asking 206 young Dutch men (all were heterosexual except for two who described themselves as bisexual) to judge the attractiveness of a woman pictured on a dating site, as well as how much they wanted to have sex with her. The woman was shown wearing either a red, black or white shirt. Some men looked at the woman in the context of using the dating site to find a one-night stand, the others in the context of searching for a long-term partner. Regardless of context, the woman was not rated more attractive or sexually desirable when wearing red. Moreover, the men said afterwards that the colour of her clothing was the least significant factor in their judgments. In a second replication attempt, the same negative results were also found with a sample of nearly 200 heterosexual American men.

Next the researchers attempted a more direct replication of a prior study that demonstrated the red effect in the context of men recruited on Amazon's Mechanical Turk website rating a woman as more sexually receptive when she was seen wearing a red shirt as compared with a white one. Importantly, Peperkoorn and his colleagues obtained the exact same study materials used in that earlier research and recruited 433 men via Amazon to rate the same woman – a sample size 17 times larger than that used in the original study. However, this time, the men did not rate the woman's sexual receptivity (based on survey items like "this person is interested in sex") any differently when she was wearing red than when she was wearing white, and this was true across different age groups and regardless of the men's current relationship status.

Just as it is wise not to place too much faith in the findings from single studies, we should also interpret failed replications with caution. These new null results do not mean there is no red effect, but they do raise questions about its robustness, and the possibility that there might have a been a bias in past research to publish positive results. A generous interpretation is that the red effect could be more significant in real interactions than in lab-based research using static photos, because the colour might influence the wearer to behave more flirtatiously, for example.

However Peperkoorn and his team made their own newfound scepticism apparent. "The lack of evidence for a red effect in our three experiments … leads us to question the robustness of the red effect in human mate preferences," they said. They further pointed out that past evidence has tended to be based on small studies and they encouraged others to perform replication attempts with larger samples. "We argue … that if red has an effect on human mate preferences, then it is likely to be small," they concluded.

Further reading

—Revisiting the Red Effect on Attractiveness and Sexual Receptivity
No Effect of the Color Red on Human Mate Preferences

Image via javacolleen/flickr