“Rude awakenings: How swearing made us human” opens with a personal anecdote.
Elsewhere, more politely, New Scientist suggests baby apes’ arm waving as an origin, and that item is, happily, not paywalled.
Wired Science articles suggest that monkey lip-smacking and, depressingly, chimps throwing [excrement] provide insight into human development. Neither item is paywalled. So you might as well read them or the arm-waving one instead. Same basic message, way better price.
This is one reason paywalls probably won’t work.
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