Louis J. Sheehan, Esquire .  In a group of chimpanzees now living in Tanzania's Mihale Mountains National Park, grooming partners sometimes both raise their right (or left) arms above their heads and grasp each others' wrists as they take turns cleaning one another. In a nearby Mihale chimp community studied about 20 years ago, grooming duos preferred to raise arms and clasp hands, palm-to-palm, as they tidied up one another.  http://louissheehan.bravejournal.com

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