Researchers Say: Fill Your Bladder To Clear Your Mind

By Patrick Morgan | March 1, 2011 6:11 pm

Before you make any life-altering decisions in the future, you may want to guzzle a few liters of water. At least, that’s according to new research that found that people with water-filled bladders are better at making decisions about their future—a finding that not only counters common sense, but also flies in the face of past psychological consensus.

Lead author of the study published in Psychological Science, Mirjam Tuk, a scientist at the Netherland’s University of Twente, landed upon this unique research topic after she drank too much coffee during a lengthy lecture. As the coffee made its way to her bladder,  she asked herself a question: “What happens when people experience higher levels of bladder control?” And with that start, she devised an experiment to test whether people’s ability to control their bladders allowed them to better control other desires.

To test this, she had volunteers either drink  five cups of water, or sip a tiny bit of water from five different cups, and after 40 minutes, she assessed the self control of each group by asking them a series of questions. The participants had to choose between instant gratification or a larger, down-the-road award; $16 in a day, or $30 in over a month from now.

The surprising thing is that the people who drank more—the ones whose bladders were full—more often chose the delayed award. It’s a surprising finding because, as Tuk explains in the paper’s abstract, psychologists believe that “visceral states are known to have a (detrimental) impact on our ability to exert self-control.” Psychologists call this “ego depletion”: the mind labors to to restrain a bodily function, making it harder to exert self-control in other areas. So how did full bladders lead to better self-control?

Tuk’s study only established a correlation bladder control with other types of self-control, but she does have a working hypothesis about what’s actually happening in her subjects’ brains. The reason is that our feelings of inhibition all originate from the same area in the brain, she explained to me in an email, and so it’s not too hard to imagine that our self-control in one area can affect—or “spill over” (get it?)—into self-control in other areas. “Hence, people who [are experiencing] higher levels of bladder control, should be better able to control unrelated impulses,” she writes.

So when you’re making any important decisions about investing your nest egg or blowing it on a sports car, you might want to down a glass of water, ignore that need-to-pee feeling, and pull the trigger on the decision. Then go the bathroom, already!

Related Content:
80beats: Eating Cheese and Meat May Boost Self-Control
80beats: Study: Restraint as a Youngster Connected to Success as an Adult
Not Exactly Rocket Science: People who think they are more restrained are more likely to succumb to temptation
Not Exactly Rocket Science: Self-control in childhood predicts health and wealth in adulthood

Image: flickr / Greg Riegler Photography

CATEGORIZED UNDER: What’s Inside Your Brain?
  • Cobalt Lion

    I’d love to read the research on Tuk’s correlation. Maybe it’s just that it seems somewhat counter-intuitive, but this just sort of sounds like an unrelated coincidence.

  • Bee

    Not to belittle those exciting results, but I doubt that 40 minutes is enough to be certain the test subject’s bladder was indeed full. I had to go to ultrasound several times and was asked to drink 1 liter water before that, so the bladder was full. First time I thought 1 hour would be enough, but turned out to take at least 90 minutes. So. Then maybe it’s a correlation with being well hydrated or having a full stomach or, I don’t know, drinking water?

  • Murfomurf

    I could imagine that the water flushes away unwanted metabolites in the blood and makes more oxygen available for brain processes. However, I haven’t read the full study to check out the methodology!

  • Sas

    Or, maybe they didn’t want to stick around to collect the money because they really had to go!

  • Adolph Oliver Bush

    This isn’t very convincing. How many volunteers? How strong was this correlation exactly?

    This is an interesting area of research, but it’s a shame the research in it isn’t better.

  • methusila

    Wouldn’t it be critical in this experiment to clarify that they will only be paid once? If it was clear that I was going to be paid once and only once I’d wait for the $30 too.

    Also , it seems the closer the numbers are the less likely the person will pick the larger amount for example, 10,000 and 10,500. It’d be easier to say I could really use 10,000 right now and disregard the loss of $500 for getting it 3 weeks quicker. But if the numbers stay at a constant doubling like 10,000 and 20,000 it’s easier to be patient, likewise if the numbers are extremely different the choice becomes very obvious 100 and 10,000. Relative significance also plays a part in determining whether or not something is important. I’m just not sure $14 is significant enough to some people to consider the pay worth the wait…

  • Harmen

    @Bee, the experimenters also asked how big an urge to pee the subjects had. Remember that your bladder doesn’t have to be entirely full, either.
    @Murformurf, no it’s a brain thing, where one part of the brain influences another. More oxygen doesn’t necessarily mean you think better.
    @Adolph, it says in the linked article, 102 subjects. I’m no psychologist, but it says in the official documents that: “People in the
    high bladder pressure condition chose more often for the LL reward (M = 4.50; SD = 1.59)
    compared to people in the low bladder pressure condition (M = 3.83; SD = 1.49).”
    So, the difference is (4.50 + 3.83) divided by 4.50
    They also state that there have been similar studies that looked for a correlation of other things that have something to do with inhibition (lust, for example). So it’s not an under-researched subject.
    Please just read the source before you start talking trash.
    Good question. They (that is, the source) do mention, though, that “Previous research has extensively examined how people deal with self-control conflicts (Hagger, Wood, Stiff, & Chatzisarantis, 2010; Vohs & Heatherton, 2000).” So I think they knew how much a difference they had to offer.

  • Abe Milanesi



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