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Needing to Pee Actually Makes You a Better Liar, Study Finds

PETER DOCKRILL
23 SEP 2015

Nobody likes feeling like they need to visit the bathroom when they can’t, but according to new research, the self-control we’re forced to exercise when suppressing an urgent desire to pee actually enables us to be better liars.

 

The theory is that the mental control we exert on ourselves when we’re trying to not think about how much we’d really like to take a leak spills over – sorry folks, but that’s the term the authors actually use! – into other areas of the brain, including the mental faculties we use to deceive others.

The “’inhibitory spillover effect” (ISE), as the researchers call it, occurs when performance in one self-control task facilitates performance in another, simultaneously conducted self-control task. To test their theory that the ISE could be demonstrated between physical control and cognitive control, the researchers devised a particularly devious experiment.

Twenty-two student volunteers were asked to complete a survey on a range of social and moral issues. Afterwards, they were interviewed by a panel, with instructions to lie about how they felt on some of the issues – and argue for opposing views as if they were their own.

To add a little fluid pressure to the situation, 45 minutes before the interview, half the participants were obliged to drink a sizeable 700 ml of water to get the internal juices flowing, while the other half of the group only had to swallow a 50 ml whistle-wetter.

And what do you know? The interview panel was well and truly taken in by the liars with a full bladder. According to the perception of their observers, the liars who drank a high volume of water showed significantly fewer behavioural cues giving away that they were being deceptive and evidenced more behavioural cues that signalled truth.

The liars who needed to pee told longer and more complex stories than the participants who felt no bladder pressure but also managed to win over the interview panel with their pressurised performances.

According to Iris Blandon-Gitlin, one of the authors of the study, bladder control and other forms of cognitive control are not as separate as we might otherwise think.

“They’re subjectively different but in the brain they’re not,“ she told Sam Wong at New Scientist. ”They’re not domain-specific. When you activate the inhibitory control network in one domain, the benefits spill over to other tasks.”

While obviously this was a very small study with a tiny sample size, the findings, which are to be published in Consciousness and Cognition, might just be worth remembering next time you score an interview for that elusive dream job for which you’re hopelessly under-qualified…