Most of us have told a white lie to manage our interpersonal relationships, but how many of them were convincing? While some of us can lie with a straight face, others are as obvious as Pinocchio. According to a recent study to be published in the journal Consciousness and Cognition, holding in your pee while trying to tell a lie could actually make you become a better liar.

“Lying requires a great deal of mental resources,” Iris Blandon-Gitlin, author of the study told PopSci. “You have to juggle a lot of information.”

“Manipulation of information such as suppressing irrelevant thoughts — i.e. telling the truth — and providing a believable story while monitoring one’s and others’ behavior, are among the tasks that the liar has to juggle.”

Blandon-Gitlin and her colleagues sought to investigate the inhibitory-spillover-effect (ISE) — the benefits from self-control in one task “spill over” to control other tasks — on a deception task by recruiting 22 college students to fill out questionnaires about their views on social issues, such as abortion and the death penalty, knowing that they would be interviewed about their opinions later. Prior to the interview, researchers asked the participants to drink 700 milliliters (ml) of water, while the other half only had to drink 50ml, as part of a (fake) taste-test experiment. After a 45-minute waiting period, the students sat for their video-taped interviews.

Some students were asked to field interview questions truthfully and the others were instructed to lie. Then they were broken down into two groups — liars and truth-tellers with urgent and less-urgent needs to empty their bladders. A completely different group of student volunteers observed the tapes, rating a number of physical and verbal behaviors that are associated with detecting deception.

In a second experiment, the same taped interviews were shown to a third group of students. Instead of assessing their behavior, the students were asked to weigh in on whether they thought the interviewees were lying or telling the truth.

Across both experiments, students who had to pee more urgently showed less behavioral cues associated with deception and were more convincing when lying about their opinions compared with those who drank less water. Those who had to pee created more intricate, complex lies, which researchers interpreted as having greater mental control. A full bladder did not have the same impact on truth-telling.

This small study suggests this full bladder technique might make deception easier as long as the desire to pee isn’t overwhelming. “If it’s just enough to keep you on edge, you might be able to focus and be a better liar,” Blandon-Gitlin told New Scientist.

The study provides supporting evidence for another 2011 study published in the journal Psychological Science, which found people with full bladders are better at suppressing their impulses for instant gratification. Peeing in the moment you feel the urge is easier and satisfying, but this could become an issue if we’re in a place that has no access to a bathroom. This suggests different activities that require self-control share similar processes in the brain, meaning engaging in self-control can enhance another activity.

So what happens in the brain that allows us to become better at lying when we have the urge to pee?

Lying is a cognitive complex task that does require a great deal of inhibitory control. For example, in order for us to lie, our brains have to inhibit the urge to tell the truth. So, if the brain is already inhibiting the urge to pee, it could make it easier for us to lie.

This is able to occur since the inhibitory network is not domain-specific, therefore, activating the network with one self-control act will activate other parts of the network. This is the OSE in full effect.

So truth be told, if you must lie, hold your pee in.

Sources: Fenn E, Blandon-Gitlin I, Coons J et al. The inhibitory spillover effect: Controlling the bladder makes better liars. Consciousness and Cognition. 2015.

Tuk MA, Trampe D, and Warlop L. Inhibitory Spillover: Increased Urination Urgency Facilitates Impulse Control in Unrelated Domains. Psychological Science. 2011.