Men who wear red appear more dominant, aggressive and angrier than those wearing grey or blue, researchers have found.

The colour red has previously been found to be linked with dominance and testosterone among males in a variety of animal species, with artificial stimuli influencing interactions.

In humans, red is seen to be more threatening than other colours and wearing it has been found to increase the probability of winning sporting events. Other studies have found wearing it increases sexual attractiveness.

Researchers from Durham University, publishing their findings in the Royal Society Biology Letters, were looking to find out if red clothing changes the perception of aggression and dominance outside of competitive settings – and if it influences the interpretation of emotional expressions.

They said there has been no prior research on the effects of colour on perceptions of aggressiveness in neutral settings. They predicted people wearing red would be rated as more aggressive, dominant and angry than those wearing blue or grey.

The photo test

Participants – 50 men and 50 women – were shown digitally manipulated photos of men and they were asked to rate them for aggression and dominance. The scientists also categorised the how the "raters" perceived the emotional state of the men in the pictures.

They were asked to rate aggression on scales from one (being extremely aggressive) and seven (extremely friendly), for dominance (one was extremely submissive and seven extremely dominant), and they selected an emotional state of angry, happy, frightened of neutral.

While there was no difference between the grey and blue T-shirts for aggression or dominant, those wearing red were rated as being more aggressive. Male participants rated the red shirts as being more dominant but colour did not influence the female participants' perception of this.

"We found that clothing colour biases the perception of aggression, dominance and anger in strangers, outside of competitive or achievements contexts," the authors concluded. "Men wearing red were rated as more aggressive and more dominant and were more often categorised as 'angry' than targets wearing grey or blue.

"Clothing colour did not influence female participants' perception of male dominance but did influence male participants' perceptions. Whether or not this sex difference reflects different biases in social perceptions requires further investigation.

"For example, the colour red distorts time perception in men but not in women, and wearing red enhanced the probability of winning combat sport bouts in male, but not female, athletes."

They said the tendency to see those in red shirts as more angry suggests colour influences the judgment of emotional expression and that red is biased towards this. The authors said: "These findings suggest a clear association between the colour red and perceptions of anger possibly related to the role of facial reddening as a natural signal of anger.

"While red images resulted in higher ratings for aggression and dominance, ratings for blue and grey images did not differ significantly. Hence, it seems to be specifically red that influences judgments of aggression and dominance."