“[Cambridge Analytica] looked at actual people. How they engaged with certain brands was put into a funnel and helped build the algorithms,” Wylie explained.

“When you look at personality traits, music and fashion are the most informative [tools] for predicting someone’s personality.”

A user’s predilection for a particular label gives, he said, a very clear indication of “populist political signalling.”

Cambridge Analytica, which was shut down earlier this year following an investigation by The Observer, was the political marketing firm headed by Trump’s former key adviser, Steve Bannon, and owned by hedge-fund billionaire Robert Mercer.

It also used user information obtained without authorisation in early 2014 – including cultural preferences such as fashion and music – to create a system that could single out voters to expose them to specific political advertising.

Before the company’s role on Trump’s election campaign, Wylie had been Cambridge Analytica’s director of research.

Recalling his first meeting with Bannon, he explained how fashion was one of the many things they examined, along with “Judith Butler, Foucault and nature of our fractured self.”

He said the pair discussed the difference between Crocs and Chanel’s little black dress as analogous for the fashion spectrum – which would become a blueprint for how the firm used fashion preferences later on.

Wylie went on to criticise the fashion industry for creating a “pre-existing cultural foundation which allowed the alt-right to grow over that time period.”

He conceded that while Cambridge Analytica “exploited the cultural narratives that the fashion and culture industry put out”, the fashion industry was responsible for creating those cultural narratives in the first place.

He added: “We need new narratives in culture, and to do a better job of showing more diversity” to direct politics along a different route.

According to the data obtained (most which came from US users), certain fans of American denim brands such as Wrangler, Hollister and Lee Jeans could be more closely linked to low levels of openness and mistrust – and therefore more likely to engage with pro-Trump messaging.

This data also showed more esoteric fashion labels such as Kenzo or Alexander McQueen tended towards a more open and imaginative fan base, which Wylie said leaned more towards typical democratic voters.

Wylie went on to explain that this data was particularly used to target the alternative right.

“When we think about fascist movements, the first thing they do is develop an aesthetic,” he said, illustrating his point with the uniforms of the Nazi party and, more recently, alternative right supremacists who, in August 2017 marched through Charlottesville in the US in a uniform of chinos and white polo shirts.

The link between fashion and psychology is nothing new, but this is the first time that it has been exploited to influence political thinking, says Wylie.

“[Bannon and I] said, if we indulge in light stereotyping, [if we look] at culture as a distribution of attributions that plays out in the wider world, we can work out where it goes,” he said.

“The thing with Crocs and the Chanel dress, one is quick, fast and regrettable, the other is enduring and iconic … it is up to you if Trump or Brexit [are] the Crocs or the Chanel of our political age.”

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