There’s an immense power to a woman in red. Who is she? Lover? Revolutionary? Priestess? Prostitute? She draws your eye and fills your mind. From Chris De Burgh’s Lady In Red (a sappy song about an important moment) to Game Of Thrones’ red woman Melisandre (with her fanatical words “the night is dark and full of terrors”), the scarlet woman has exerted a powerful pull.

This season’s catwalks were full of reds. Shoes in crimson velvet, fit for a regency duchess. Dresses in poison apple shades. Coats and jackets the colour of blood and fire. Why so much red, now? It’s easy to say bright shades pop on Instagram and in online stores, but there’s more to it than seeking easy clicks from novelty-seeking browsers. Red is the colour of both danger and attraction, of stop signs and come-ons, and it’s always been that way.

Seeing in red

The reason we, as humans, developed colour vision isn’t fully understood. At some point in our evolution, though, we started to distinguish red from green. One theory is that compared to green, red foods tend to be higher in calories, and in protein, both of which are necessary for healthy brain function. Being able to spot the ripest berries to eat may well have helped our ancestors stay sharp and stimulated the growth of new brain cells.

If that’s the case, the fact we find it such an intoxicating shade goes back to the beginnings of our evolution. This would also explain why in one study, researchers found that being exposed to red increases our appetite.

“Another hypothesis is that red is an honest signal of a physical condition,” says Professor Robert Barton, a Durham University anthropologist. When we’re angry or aroused, blood flushes close to the surface of our skin. “It has been shown to happen irrespective of skin colour or tone.”

As a species, the majority of our brain function is dedicated to understanding and processing social interaction, “so even seemingly tiny cues – like a flushed face – alert your brain to the fact that something, danger or sex, is about to happen.”

This, researchers have argued, would also explain why red makes us more attentive to detail. If the colour is biologically marked as ‘important’, our brains switch to alert mode; sounds and smells are heightened, our vision becomes sharper, and our blood pressure rises to prepare for fight or flight. The person who’s flushed (or, in the case of sporting teams, wearing red) seems more aggressive and therefore dangerous; in turn we prepare to flee.

“In one study they found that giving participants exam papers with red covers altered their performance by making them act more impetuously,” says Kassia St Clair, author of the bestselling book The Secret Lives Of Colour. “It taps into the action part of our brain, probably at the cost of higher cognitive reasoning.”

In 800AD, Charles the Great was crowned ruler of an empire that spanned almost the entirety of Europe. At his coronation he wore all red. “Through that colour,” writes historian Michel Pastoureau in his book Red: The History Of A Color, “he became the true heir of the ancient Roman emperors.”

In 1587, when asked if she had any final words before her execution, Mary Queen of Scots slipped off her black velvet over-dress revealing a bright crimson petticoat; her final statement was to be beheaded in the colour of Catholic martyrs.

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“It’s a bold, defiant act every onlooker would have understood. She was casting herself in the role of a martyr, dying for her faith at the hands of her Protestant cousin,” says St Clair. Even within pop culture, Vivian’s red dress in Pretty Woman borrows from a long tradition that equates prostitution with scarlet.

Depending on who’s wearing it, the colour represents a different type of power: noble, divine or sexual. It’s for this reason that within the Roman Catholic church, red has played a central role for two millennia. “Hell is represented as red, but it’s also the colour worn by the Cardinals, the Pope’s closest advisers. These are the top and bottom of the spiritual scale: both are red and both are powerful,” continues St Clair.

Still, some have overlooked its power over the years, considering it simply poetic licence.

A winner’s choice

In 2005, though, in a wide-scale study spanning a number of years, German sports psychologists at the University of Munster found that teams in red kit scored 10% more in any competition than if they were wearing another colour.

In the past 10 years, exploring the neurological and psychological impact of colours has become an ever-growing field and being exposed to them – and to red in particular – has been shown to subtly alter everything from our blood pressure to the balance of neurochemicals in our brains. And these effects vary depending on the context.

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Drivers cut-off by a red car react faster and more aggressively. Women who wear red are seen as more attractive by men and waitresses in red are tipped more highly by male customers. In one research project, French scientists even found that women in red lipstick are more often approached by men in bars.

Sex and lust, anger and impetuosity: far from being the stuff of university lectures, red’s power over us is bold, vital and immediate.

The very first symbol

In 1934, archaeologists began to excavate a cave, partially obscured by cacti, near the Israeli town of Nazareth. Within the cave, the leader of the dig, René Neuville, a French diplomat and prehistorian, found human remains that were almost 100,000 years old. They’d been buried with care and ceremony. So much care, in fact, that next to each grave the historians found fragments of red ochre – a type of red-coloured stone.

Dr Erella Hovers of the Hebrew University of Jerusalem worked on further excavations of the site in the early 2000s. As she told the BBC at the time: “The red ochre meant something to [the people who buried their dead there], exactly what we do not know… [but] it is an example of symbolic thought, the ochre symbolised death.” The discoveries were important because they indicated that as early as 100,000 years ago our ancestors had begun to understand symbolism.

“Right at the beginning of ‘modern’ human thinking, the colour red was there. It was the first symbol,” says Dr Spike Bucklow, a research scientist at the University of Cambridge.

From then it appears again and again. History is awash with violent reds, dominant reds, seductive reds and reds that represented fertility, new life and death.

Barton points out that it’s difficult to untangle science and history. “It’s possible that our brains now respond to red because of thousands of years of social and cultural conditioning.” If red stone was the first symbol used by man, it stands to reason that 100,000 years of red symbolism would leave a neurological mark.

“It’s equally possible, though, that it only ever developed that meaning because we have an underlying biological predisposition to it,” she adds.

Whether it’s nature or nurture, Pastoureau points out that as the colour of blood, flames and meat, red has always been present in human life. Danger, action and violence or love, warmth and sexuality, red embodies extremes of humanity. Little wonder that it has the power to make our pulses race.

Images: Brooke Cagle / iStock / Rex Features