YouTube and Reddit users who engage with anti-feminist content can become radicalised to subscribe to alt-right beliefs, according to an analysis of 300 million comments on each platform.

Manoel Ribeiro and his colleagues at the Swiss Federal Institute of Technology in Lausanne analysed the comments posted to 115 Reddit forums and 526 YouTube channels between 2006 and 2018 to see whether there was overlap between communities that expressed hate towards women, sometimes dubbed the “manosphere”, and alt-right groups.

Ribeiro wanted to investigate potential ties because of media coverage connecting people who self-describe as “involuntarily celibate”, also known as “incels”, to mass shootings – one such man was found guilty last week of murdering 10 people in Toronto, Canada, in 2018. “When the media covers these communities, they associate incels with the far right,” says Ribeiro. “Can we find evidence for that?”

The researchers tracked the type of content each user engaged with, looking at general news, manosphere and alt-right content. They conducted separate research on Reddit and YouTube, rather than trying to identify people crossing between the two. The forums and channels investigated were chosen as they have been associated with anti-feminist and alt-right groups in prior academic work.

The team divided anti-feminist groups into four categories: members of the anti-feminist, male-separatist group Men Going Their Own Way (MGTOW), men’s rights activists, incels, and “pick-up artists”, who share strategies for convincing women to have sex with them. “There’s a lot of anti-feminism in the far right, and I think this resonates with these anti-women communities,” says Ribeiro.

To look for evidence of radicalisation, the team looked at people who in 2016 commented on YouTube videos classified as anti-feminist, and on general news videos, but had no engagement with alt-right videos and compared this with what they were doing in 2018. MGTOW members were most likely to later engage with alt-right content: by 2018, 21.9 per cent had begun commenting on alt-right videos, while less than 10 per cent of general news commenters had migrated to alt-right videos.

Read more: Gamifying hate: How alt-right extremists recruit and mobilise online

Despite the media’s connection between incels and alt-right beliefs, incels were least likely to turn up in alt-right communities, with 15.2 per cent of those who commented on incel videos in 2016 ending up engaging with alt-right content in 2018.

The team’s analysis of Reddit found similar results, but in general migration from the manosphere to the alt-right was higher on Reddit than YouTube. In 2018, the alt-right on YouTube and Reddit comprised almost 850,000 users, while the manosphere on both sites was 1.5 million people strong.

“These communities were allowed to grow for a very long time, with platforms having a very lax moderation policy,” says Jacob Johanssen of St Mary’s University, London, who has previously analysed the manosphere.

YouTube told New Scientist that its policy is to remove content that promotes violence or extremism. The company declined to answer specific questions about the research. Reddit did not respond to a request for comment.

Johanssen says the team’s research does seem to show a strong link between the manosphere and the alt-right, but he warns that it is difficult to identify varied communities as a single mass. “These communities are very heterogenous in themselves,” he says. “Specifically with incels, there isn’t one incel community.”

Ribeiro hopes investigating the content of the comments posted may help understand the causal routes of radicalisation, in the hope of preventing people moving into more violent fringe groups. “A lot of these communities are benefitting from the fact they’re in these mainstream platforms for a long time,” he says. “It raises questions of how to spot these problematic questions quickly and take action.”