A decade ago, just before the Brexit referendum and Donald Trump’s presidential victory over Hillary Clinton started the febrile era we are still stuck in, there was a common understanding of the main way social media messed with our minds – by presenting absurdly idealised versions of people’s lives, and thereby making other human beings miserable.

“We see wild parties, holidays, weddings, family outings and close-knit friendship groups,” wrote one Guardian journalist in 2015. She went on: “Apart from commemorating a deceased person’s life, you’ll be hard pushed to find a really bad moment in your feed.” Here, it seemed, was a modern iteration of the opium always purveyed by free-market capitalism, resulting in a constant stream of personal happiness and precious little recognition of life’s more difficult aspects: social strife, inequality, disagreement.

Of course, users still post impossibly upbeat depictions of who they are and what they do. But for the most part, we now live in a completely different era. A lot of explanations for this centre on what has become the internet’s most rampant kind of content: the short-form video popularised by TikTok, and then spread further by such imitations as Instagram’s Reels and YouTube Shorts. Those innovations have triggered a complete upending of the online world: rather than posts about personal contentment and bliss, as our fingers scroll and swipe, we are now fed a diet of violence, prejudice, damage and social unrest. It is warping our understanding of the world, and rapidly reshaping our politics.

Be in no doubt: this is how the political future is being decided, as the past week has vividly demonstrated. Before his murder, the rightwing US activist Charlie Kirk had amassed more than seven million TikTok followers – and as one US writer put it, the essential story of his assassination was about “an influencer shot to death at a school in front of a crowd of smartphones”. Consider also what happened on Saturday in London – when, after months of rallying cries going out online, an estimated 110,000 people gathered at the instigation of the agitator and influencer known as Tommy Robinson, and were addressed via the internet by Elon Musk.

Aside from the latter’s platform-cum-hellhole X, Robinson........

© The Guardian