What forensic psychology and evolutionary biology tell us about how to win The Traitors

Hoods up, torches lit, knives sharpened: viewers across the UK are ready for another delicious finale of The Traitors this evening, the TV game show where contestants try to uncloak the ruthless (not strictly real) murderers who walk among them.

For psychologists – professional and armchair alike – The Traitors is a goldmine of devious human behaviour to pick apart and analyse. And it isn’t just psychology. Game theory, human evolution and criminology are just some of the scientific fields that offer clues about the show’s Machiavellian dynamics.

We surveyed experts in treachery (academically speaking…) to find out what it truly takes to win The Traitors. Warning: spoilers ahead if you aren’t up to date with the show.

Watch out for conformity bias

“Having a strong characteristic seems to be something that other people notice as being influential and potentially threatening,” says forensic psychologist Clea Wright, who hosts a podcast about The Traitors with colleagues from the University of Chester, UK. She singles out contestants like Yin (too intelligent), Elen (too emotional) and Armani (too confident).

Their downfalls are likely to have been linked to conformity bias, the trait in humans that makes most of us conform to social norms. Individuals who don’t conform may be disliked or distrusted.

This isn’t the place for altruism

Emily Emmott, an evolutionary anthropologist at University College London, says players should keep in mind that “in evolutionary literature, altruism doesn’t really exist”.

“Remember, it’s not a cooperation game,” she says. “It’s a game of deception, a survival game. You need to be there at the end to win. That’s a mistake some players make because they’re too trusting of the people they’re close to.”

Emmott says that we evolved to help ourselves ahead of others, so any altruistic behaviour seen on the show has a selfish benefit behind it. And such apparent altruism isn’t a bad tactic, whether you’re a faithful or a traitor.

“In the game context, being cooperative serves as a signal of trustworthiness. A good example might be overtly not going for the shield [which protects you from the next murder] during the show’s tasks.”

But here’s where Machiavellian intelligence comes in – because everyone knows the rules of the game, a good player won’t take altruistic behaviour at face value. “In this game, it’s not an honest signal because there could be ulterior motives to you cooperating,” says Emmott.

So watch out for the nice guys. An analysis of thousands of messages between players in Diplomacy, a game that shares similarities with The Traitors, found that players who were excessively polite were more likely to betray others.

Beware of in-group bias

“We know from social psychology that when people form social groups, they have what’s called an in-group bias, and this can be really accelerated in The Traitors,” says Wright. “[Contestants] display preferential behaviour to people who are in that group with them.” This is why it all went wrong for Minah after recruiting Charlotte as a traitor.

For Minah, who always recruited female traitors, her group was the so-called sisterhood she created. “She very much identified it as a sisterhood, she used the word a lot,” says Wright. “The problem was, Charlotte already had a strong group identity with the faithfuls. So when she was recruited, kind of against her will, she didn’t have any allegiance to the new group.”

And what happened? Charlotte double-crossed Minah immediately, and Minah was voted out on the next night.

Wright says the same in-group bias can lead to a herd mentality when players are voting, and an illogical trust in people within the game.

What makes a good liar?

Nervous or incoherent answers to questions are generally regarded with suspicion, even if someone is telling the truth. That’s because those behaviours are tied to stereotypes about what people think liars do. A better giveaway is people who always say the same thing, says Emma Barrett, a psychologist and criminologist at the University of Manchester, UK.

“One thing to look out for is someone who always tells the same story in exactly the same way and doesn’t really elaborate when they retell it,” she says. A story might sound plausible, but when we repeat it we usually add details as we remember them. “People sometimes mistake consistency for honesty. But that’s not how recall works in genuine memories.”

Think like a scientist

“A mark of a good detective is a high tolerance of ambiguity. They won’t come to a conclusion quickly,” says Barrett. It’s similar to thinking like a scientist: “You might have a plausible hypothesis about something. Then you’ll ask yourself about the assumptions you’re making and the gaps in your understanding. You have to actively look for evidence that disconfirms the hypothesis you’re generating.”

Faithfuls aren’t very good at that on The Traitors, but another tactic they could use is to encourage a suspected traitor to talk more than they’d like to. It’s about giving them enough rope to hang themselves with, says Barrett.

“If you’re a faithful, a good strategy to detect a traitor is to subtly encourage them to talk,” she says. “For instance, if you were a police officer and you wanted to know if someone had given you a false address, one question you might ask is, ‘Oh, how do you get there, what’s your nearest station?’”

If in doubt, try game theory?

An uninformed majority will always lose to a fully informed minority. It was on this basis that Russian psychologist Dimitry Davidoff created Mafia – the parlour game on which The Traitors is based – in the 1980s. Since then, Mafia has been used as the basis of many game theory experiments and models.

The good news is that Davidoff wasn’t quite right. He believed that the faithfuls’ probability of outing the bad guys is no better than chance. But many of the studies that model the game find that the chances of victory are roughly equal – and even tipped in favour of the faithful in live games, possibly because of the weight of the lies that traitors have to tell.

In other words, forget cold mathematics. If you really want to win The Traitors, you simply have to be more devious than everyone else.