Photo: United Artists

It is really, frustratingly hard to change someone’s mind. Facts won’t do it, and well-meaning ad campaigns generally don’t work very well either. And yet there is one little corner of the internet in which minds are changed almost every day: the subreddit ChangeMyView.

On the forum, people post a belief or opinion they currently hold and then invite the rest of the commenters to take their best shot at changing that belief. (Recent postings include “Free will doesn’t exist because we don’t author our thoughts” and “Really old people should just not vote.”) And the thing is, sometimes this actually works. The beauty of the forum is that posters openly acknowledge if their views have changed thanks to the facts that have been presented using an appropriately nerdy delta symbol to indicate “change.” ChangeMyView becomes, therefore, the ultimate laboratory to test a question that’s pretty near impossible to test in real life: What makes people change their minds?

Recently, the subreddit inspired scientists at Cornell University to investigate just how this is happening. They found that the commenters on ChangeMyView don’t typically win people over with empty, angry, fighting words. Instead, Redditors who post their stances actually have to defend why they believe what they do, and posters who take issue with these beliefs must argue their own position with calm rationality.

Here’s a breakdown of what the researchers found after analyzing more than two years’ worth of discussions on ChangeMyView:

Being popular helps. Having a crowd on your side makes the other person question his own view and start to wonder, “Everyone can’t be wrong …” It also helps to be among the first to try to convince the person that she’s on the wrong side of history. The later the argument, the less persuasive it seems to be. A discussion that drags on too long is probably not going to change any minds. A little volleying is fine – the other person has to defend their point of view, too. But too much back and forth – specifically, five rounds – and you might just solidify the other person’s stance on the issue. Consider the language. Our experts here point out that longer, more developed thoughts are much more convincing. “[L]onger replies can be more explicit and convey more information,” the authors say. Don’t make the mistake of just rambling on, however. The researchers add that “naively making a communication longer does not automatically make it more convincing (indeed, sometimes, more succinct phrasing carries more punch).” Other insights: Use different words from the initial argument, and, of course, cite your sources.

Additionally, the Washington Post suggests hedging your arguments, a strategy that might seem counterintuitive and potentially weakening, but may make for a more nonthreatening argument.

Granted, this is a study based on an internet forum where people go specifically to challenge others to change their minds, suggesting that these Redditors are likely more open to the idea of changing their opinion than people you might find in a regular old comments section or on Twitter (or in real life, for that matter). But it can’t hurt to have a few tricks up your sleeve the next time you’re trying to convince your friend that the Earth is indeed not flat.