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Male chimps socializing Photo Credit: Kyoto University, Kumamoto Sanctuary |
In Italy, it has been said, there is a proverb for everything.
Chi non piscia in compagnia o è un ladro o è una spia -- "Whoever doesn't pee in the company of others is either a thief or a spy" -- goes one such saying, describing a communal act that in Japanese is known as tsuré-shon.
Social urination can be found represented in artwork across the centuries and around the world, and even today continues to be represented in cultural tropes. Now, researchers in Japan -- observing chimpanzees -- are suggesting that this phenomenon has evolutionary roots even deeper than previously expected.
Despite decades of research into other contagious behaviors such as yawning, contagious urination has never been studied scientifically in any species. To tackle this, a team at Kyoto University conducted 604 hours of direct observation at the University's Kumamoto Sanctuary, documenting 1,328 urination events. The researchers analyzed whether these were aligned in time, triggered by nearby individuals, or influenced by social relationships.