If you want to tell someone a fib then make sure you have drunk a couple of pints of water, because scientists have found that we lie more convincingly when we need to tinkle.
California State University researchers were investigating the "inhibitory spillover effect", which is when our focus on one task facilitates the performance of another.
Needing to wee apparently improves your ability to tell a convincing lie.
Participants drank small (low control) or large (high control) amounts of water.
Next they lied or told the truth to an interviewer. Then observers came in to try to deduce whether they were lying or not.
People with full bladders were more convincing liars than those who had not had as much to drink.
"In the high-control, but not the low-control condition, liars displayed significantly fewer behavioural cues to deception, and provided longer and more complex accounts than truth-tellers," the researchers said.
Scientists have said that this is because lying is an incredibly complex cognitive task, but needing to empty your bladder activates your brain's inhibition control centres.
These are the same centres that inhibit our need to tell the truth.
