If there's anything more troubling than grown men doing YouTube stunts, it's grown men doing racist YouTube stunts. Or, as they would call them, "social experiments".

Amateur actor James Slattery, from Kent, was convicted this week of racially aggravated harassment after conducting one of his "experiments" in Liverpool. While being filmed, he told a black woman that he "hated black people" and asked her if her family was "from a tribe". After publicly humiliating the woman, he then came clean. "Don't worry," he told her, "it's a social experiment."

Slattery was sentenced to eight weeks in prison, suspended for 12 months (meaning he'll serve no jail time), and ordered to pay £200 compensation to victim Sharna Sinclair. His defence was that he was trying to "raise awareness" of racism – but how exactly "being openly racist to someone, as a joke" serves to move the conversation forward is anyone's guess.

Although there appears to be no footage online of his harassment of Sinclair, what does exist on YouTube is another one of his videos – filmed on the same day in Liverpool's Slavery Museum. In it, Slattery approaches a black man, points at an exhibit and asks him, "Did your lot make all this sort of stuff?" He carries on, while most of the white passersby shake their heads but fail to challenge him. The video culminates with him telling the man: "Black people were slaves for a reason… There was nothing else between the ears, you had the build for slavery."

Slattery's video proves nothing, besides the fact that – as already recognised within the black, Asian and minority ethnic community in the UK – white people need to do a better job of supporting people who are being racially harassed.

The video he was prosecuted for is part of a genre of "social experiment" YouTube pranks that revolve around white men mocking ethnic minorities in the UK, the US and beyond. The most common are "hood pranks", where smug white boys head into black neighbourhoods in America and aggravate people by, for instance, stepping on their Jordans, egging their cars or calling people "neighbours" (but making it sound like "niggers"). They splice together the worst footage of the people they encounter, with "hood pranks gone wrong" videos showing the YouTubers being beaten up or having guns pulled on them. It's true that a lot of the makers of these videos are smarter than Slattery was, using actors to portray the black men and women they abuse. But in general, it's nothing more than lazy racism.

YouTuber Joey Salads, for instance, produced two controversial videos in late 2016 – a year marked by a number of prominent shootings of unarmed black men by police, and months of Donald Trump's inflammatory rhetoric that stretched tensions between the black and white communities in the States. In the first video, Joey wanted to test the idea that Black Lives Matter is "racist". To do so, he went into a white neighbourhood and held up a "Black Lives Matter" sign. Hardly anyone cared. He then went into a black neighbourhood, held up an "All Lives Matter" sign and was "beaten up" (he wasn't beaten up; someone just knocked the sign out of his hand).

In his second video Joey left a car in a black neighbourhood covered in Trump stickers. The car was destroyed. It was later exposed that the video was a fake, and that Joey had worked with the black men who appeared in it. In an interview with another YouTuber, H3H3, Joey said he "never intended for it to generalise the entire black race". He's since taken down both of these videos, but it's hard to take his statement seriously when his "hood prank" videos still remain on his channel. The stereotype of black men – and, to a similar degree, black women – as being violent and aggressive is one so many of us are desperately trying to leave behind. It's a hangover from the era of slavery, exacerbated due to our "urban" status and the fact that we are disproportionately affected by poverty and treated terribly by the police and the criminal justice system.

A lot of us do so much to become "acceptable" for white society, to flatten and modify our blackness. We straighten our hair, cross the road when we think we might scare someone, lower our voices and eyes to be demure and dress plainly. So the way we are portrayed in YouTube videos matters just as much as how we are portrayed in the mainstream media. It all feeds into a narrative which ultimately sees us more likely to serve custodial sentences in the UK for the same crimes that white people commit, and struggle to get jobs in certain industries.

Not all social experiments featuring race are bad. Jane Elliot spent years putting together her infamous "Blue Eyes vs Brown Eyes" project, an extreme experiment filmed for Channel 4 that created segregation based on eye colour. It aimed to show how physical differences between people can manifest into racism and division.

But even with seemingly meaningful YouTube social experiments and pranks, it's always people of colour and women who bear the brunt. In a widely shared video of a woman walking around New York for ten hours and being sexually harassed by a range of different men, it was quickly picked up that very few white men were shown. "Racists are actually using the video – whose intention is to comment on sexism – to validate their racist beliefs," wrote Alicia Lu for Bustle.

The main outcome of YouTube social experiments seems to be cementing harmful stereotypes that black people are prone to violence and aggression, and with the rise of Facebook Live and its ilk we're only likely to see more of them.