Forget Wednesday Revs, we’re spending our Wednesday evenings watching Traitors. For those who haven’t seen it, Traitors is a TV show all about lies, deception, and guilt. Members of the public are invited to a castle and assigned to one of two groups: either “faithful” or “traitor”. The faithfuls must convince the others of their innocence and try to find the traitors; the traitors must hide their identity and “murder” a faithful each night. The catch? If only faithfuls remain at the end of the series they share the prize money; if a traitor remains in the castle, they steal every penny.

Traitors is not the only TV show that revolves around lying. Whether you’re watching Nativity each Christmas to see Mr Maddens lie about his Hollywood connections, never miss an episode of your favourite true crime podcast, or can’t look away when the Would I Lie to You? panellists contradict themselves when sharing stories (or fantasies) from their past, lying is addictive to watch. Even if not the focus of the show or film, lying is often woven into the script as a device to drive the plot forward; Friends just wouldn’t be the same if Ross and Rachel told each other the truth.

Despite being a complex neural process, humankind are not the only species that loves to lie. Frogs lower their voices to sound larger and ward off competition, and the drongo is known to mimic the alarm call of meerkats to scare them into hiding and steal their abandoned food. Humans are, however, seasoned professionals.

“The more you lie, the more effortless lying becomes.”

Why do we lie so frequently? Lying offers a way to manipulate those around us to get what we want. This could be for monetary gain, to win the favour of someone we want to impress, or to avoid a punishment. Lying, and getting away with it, activates the brain’s reward system and releases adrenaline, making us feel excited. Lies that benefit a group, whether friends or family, release oxytocin making us feel closer to those we have lied to help or protect.

What happens when we lie? Telling a lie causes increased activity in the frontal-parietal cortex (the area of the brain responsible for sensory integration, decision making and planning). The amygdala (a part of the brain involved in the processing of emotion and memory) produces a response when we lie causing a negative feeling associated with guilt. Lying can be stressful, meaning cortisol, the stress hormone, is released.

In the long term, some have suggested that lying can actually change the structure and functioning of our brains. Studies that looked at blood flow while people lied showed that, with repetition, the response in the brain’s emotional system diminished. Elevated cortisol can damage the amygdala meaning its activity dulls as we lie more often, lessening the feeling of guilt. This is even more pronounced when there are no consequences to lying and when the lie results in a reward. The brain is rewired. The more you lie, the more effortless lying becomes.

“Human beings are social animals and we seem to understand that our bonds with other people are fragile.”

There has been substantial research into pathological liars (people who lie compulsively and often without a cause or goal). Studies have shown that people who lie more often have more white matter in the brain, at the population level. White matter links different brain regions and is involved in communication between them, meaning it is important for decision-making, moral reasoning, and adhering to rules. Whether this increased white matter is a cause or effect of lying is unclear. Does lying cause more white matter to be laid down or are those who naturally have more white matter predisposed to become liars?

So, lying is a slippery slope, but most people do not end up in prison for fraud or perjury. Most people tell small lies infrequently, with the majority of lies being told by a small minority of the population. Why do we ever choose to tell the truth if we can gain by lying? It could be that we want to view ourselves as moral and upstanding members of society. Most people don’t mind “forgetting” to remind their supervisor about an essay but it’s unlikely they would be comfortable going through their bag and stealing their wallet. Human beings are social animals and we seem to understand that our bonds with other people are fragile. Empathy stops us from causing pain to those around us. Psychopaths, who lack this moral judgement within them, can often lie very easily.

Despite this understanding that lying is wrong, we love to watch it play out on our TV screens. Why is it that Traitors is so addictive to watch? Maybe we like to live vicariously through the show and see people tell the lies that we would not dare to tell in our own lives. Maybe there is a part of us that wants the traitors to be caught to see justice play out in real-time - or perhaps, perversely, are we excited to be in on the secret and want to see the traitors succeed? Or maybe it is simply host Claudia Winkelman’s roll-necks and eyeliner that keep us coming back for the next episode.