A researcher, Mirjam Tuk, from the faculty of behavioural sciences at the University of Twente in the Netherlands won an Ig Nobel prize in medicine for her research on decision-making and bladder control.
One of her colleagues had argued that hunger and sexual arousal could make you more impulsive so she wondered if there were physical visceral experiences that might have the opposite effect. In the experiment she gave people water as part of what they thought was a water-tasting experiment. Half the group were given full cups while the other half only had sips.
They were all then given 45 minutes of tests followed by an impulse control test similar to the famous marshmallows test.
Those people who urgently needed to go to the lavatory tended to opt for the larger, deferred reward.
Tuk speculates (in the absence of neuro-imaging or actually measuring how full the participants’ bladders were) that, because the area of the brain responsible for controlling urine retention also controls other things such as cognitive responses, controlling impulses leads to more rational decisions.
Maybe if you have important decisions to make and you need to run to the lavatory you put off making the decision because you can’t concentrate on anything else but getting to the loo? Or if you were anxious about getting to the lavatory would you be more likely to make a quick decision so you could go?