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ELI5:Why does moving our mouth or sticking out our tongue make a difficult task seem easier?(r/explainlikeimfive)
It has to do with the development of fine motor skills, and language. Essentially they coevolved. Fine motor skills in hands enabled tool use at the same time it allowed for complex gestural communication.
Complex vocal communication relies on fine motor control of tongue and lips. So the same area of the brain is involved in both. (Also why people gesture with their hands when they talk)
The author of this book talks about it. www.amazon.com/Next-Kin-My-Conversations-Chimpanze…