Credit: George Hodan/public domain

(Medical Xpress)—A study conducted by a team of researchers at California State University has led to evidence that suggests people with a full bladder make better liars. In their paper published in the journal Consciousness and Cognition the team describes their study, what they found and offer a theory on why improved lying may be tied to delaying urination.

A prior study conducted by Mirjam Tuk of Imperial College, four years ago, led to evidence that people with a full bladder were in general better at resisting impulsive behavior. Team lead Iris Blandón-Gitlin explained to New Scientist that the group wanted to find out if those with a full bladder might be better liars as well. The thinking is that impulse control might be related to bladder control in the brain—by turning on one feature we might be inadvertently turning on another, one that also helps with another form of self control—lying.

To learn more, the researchers asked 22 volunteer students to fill out a questionnaire regarding issues believed to be socially or morally controversial. After completing the questionnaire, half of the volunteers were asked to drink 50ml of water, and the other half 700ml of water—forty five minutes later, each was asked to lie about two of the issues they felt strongly about during an interview. The researchers were then able to compare answers from each given during the questionnaire with those given orally afterwards.

In studying the results, the researchers found that those with a full bladder were able to better disguise the lies they told, as evidenced by an inability by the interviewers to detect signs of lying by the volunteers. They also found that those with a full bladder gave longer more detailed answers when lying, perhaps in an attempt to cover their lies better.

Blandón-Gitlin suggested that impulse control and bladder control perhaps rely on a common neural resource, and thus activating one, activates the other. She is quick to point out that she and her team are not suggesting that people such as U.K. Prime Minister David Cameron (who famously uses bladder control to focus his thoughts) hold their water to help them lie better, but instead suggests that those who wish to lie, might find it easier to do so if they hold off using the lavatory—but only to a point, waiting until the desire to urinate becomes overwhelming likely would skew behavior dramatically.

More information: The inhibitory spillover effect: Controlling the bladder makes better liars, Consciousness and Cognition, Volume 37, December 2015, Pages 112–122. Journal information: Consciousness and Cognition The inhibitory spillover effect: Controlling the bladder makes better liars,, Volume 37, December 2015, Pages 112–122. DOI: 10.1016/j.concog.2015.09.003

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