Researchers discovered the brains self-control mechanism provides restraint in all areas at once.
They found people with a full bladder were able to better control and hold off making important, or expensive, decisions, leading to better judgement.
Psychologists from the University of Twente in the Netherlands linked bladder control to the same part of the brain that activates feelings of desire and reward.
The study, published in the journal Psychological Science, also concluded that just thinking about words related to urination triggered the same effect.
Their findings contradict previous research which found people who are forced to restrain themselves put more pressure on their brain and found it difficult exerting self-control.
Dr Mirjam Tuk, who led the study, said that the brains control signals were not task specific but result in an "unintentional increase" in control over other tasks.
"People are more able to control their impulses for short term pleasures and choose more often an option which is more beneficial in the long run, she said.
"The brain area sending this signal, is activated not only for bladder control, but for all sorts of control.