British ‘redcoats’ may have been helped to victory in the Battle of Waterloo by the colour of their uniforms, research suggests.

Men wearing red are seen as more aggressive, angry and dominant than those dressed in blue or grey, a study has shown.

So Napoleon’s blue-clad troops would have been at a distinct psychological disadvantage when they confronted the Duke of Wellington’s forces in 1815.

A red tie is considered a ‘power tie’.

Red often signals aggression in animals, and appears to have a similar effect in humans, according to the researchers.

They believe the colour red could be having a major impact in business, social situations and on the sports field.

The study involved showing 50 male and 50 female volunteers photos of men wearing different coloured T-shirts.

Those wearing red were rated as more aggressive and angry than those in blue or grey. Male participants only also viewed other men in red as ‘dominant’.

Anthropologist Diana Wiedemann, from the University of Durham, said: “We know that the colour red has an effect on the human brain. This is embedded in our culture, for example the idea of wearing a red tie – known as a ‘power tie’ – for business, or issuing a red alert.

“The implications of our research are that people may wish to think carefully about wearing red in social situations and perhaps important meetings, such as job interviews. Being perceived as aggressive or dominant may be an advantage in some circumstances but a disadvantage in others, for example where teamwork or trustworthiness is important.”

Being perceived as aggressive or dominant may be an advantage in some circumstances but a disadvantage in others, for example, where teamwork is important

Previous research by the same Durham scientists, led by Rob Barton, has shown that wearing red can promote aggression and competitiveness in sport.

They are currently talking to organisers of combat sports about introducing new rules to avoid the colour being used to unfair advantage.

The new study, published in the Royal Society journal Biology Letters, is believed to be the first to investigate the effect of colour on perceptions of dominance and aggression in a neutral setting.

As part of the research, images of men were digitally manipulated so that they appeared to be wearing a range of differently coloured T-shirts.

Volunteers then rated them on a scale of one to seven for aggression and dominance.

Participants were also asked to guess the emotional state of the man in each image. For those wearing red, they tended to choose ‘angry’ over ‘happy’, ‘frightened’ or ‘neutral’.

Barton said: “Taken together, our findings suggest a clear association between the colour red and perceptions of anger, possibly related to the role of facial reddening as a natural sign of anger.”

The scientists pointed out that only the effect of men wearing red was tested. How a woman in red might be perceived was a topic for future research.

The redcoat was part of the British Army uniform for more than 200 years.

Over time it evolved from being standard issue for infantrymen to having a purely ceremonial function.

Its official adoption dates from the creation of Oliver Cromwell’s New Model Army in 1645. From the late 17th century to the early 20th century, the uniform of most British soldiers included a red coat or coatee.

From 1870 onwards, a more vivid shade of scarlet was adopted by all ranks, having previously been worn only by officers, sergeants, and cavalrymen.