Human evolution; hand signals in us, apes and monkeys (Introduction)

by David Turell , Thursday, September 12, 2019, 15:41 (1687 days ago) @ David Turell

We certainly do a lot of communication with our hands as we speak. Other primates also use hand signal:

http://nautil.us/issue/76/language/the-communication-we-share-with-apes?mc_cid=c9f8dafe...

"Many primate species use gestures to communicate with others in their groups. Wild chimpanzees have been seen to use at least 66 different hand signals and movements to communicate with each other. Lifting a foot toward another chimp means “climb on me,” while stroking their mouth can mean “give me the object.” In the past, researchers have also successfully taught apes more than 100 words in sign language. “The idea is to look at language, not just as speech, but seeing it as a constellation of many cognitive properties,” says Meguerditchian.

"Most language properties involve asymmetric organization of the human brain between the two hemispheres. Given that gestures in primates seem to involve several key properties that underpin spoken language, Meguerditchian wants to see if primates undergo similar brain asymmetry when they gesture to each other. “If you want to understand the origins of language, you need to understand not only animal cognition and communication but also its brain specialization in comparison with humans, and that is what we do in primate species,” he says.

"Given both primates and humans can communicate through gestures, it provides a way of comparing how gestures are related to brain asymmetry for language and to unravel whether there are differences in how each species communicate. Meguerditchian is studying both adult and baby baboons to see which gestures they learn and the parts of their brains that might be involved. “When baboons invite someone to play, they will use their hands,” he says. “Baboons are also able to point to food they want and use gaze, like children can.”

"In human babies, which learn to gesture at objects before they can speak, the left side of their brain seems to be engaged when they do so. Certain regions on the left side of our brain, such as Broca’s area, are especially important when we speak. Meguerditchian is using magnetic resonance imaging to study baboon baby brains to see if they use a similar part of their brain when they learn to gesture. “The questions is, if language is mostly in the left hemisphere in humans, what about gesture in non-human primates? If it is the same system, which was used by a common ancestor between us, gesture in baboons might also be related to this left hemisphere specialization of the brain in baboons.”

"So far, early results from 27 brain scans of baby baboons suggest that his hypothesis is correct, and apes use similar asymmetric brain areas when they gesture as humans do when they gesture and speak.

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“'The visual aspect of language is much more important than linguists used to believe,” says Sandler, who is leading a project called the Grammar of the Body (GRAMBY). Part of the work has involved studying the complexity of newly emerging sign languages and sign language in a number of different cultures. “Different parts of the body convey different linguistic functions,” she says. “The hands convey words, but the intonation, so the rise and fall of voice, is conveyed in sign language by facial expressions and different tilts of the head.”

"She and her colleagues also studied video footage of chimp displays at a Zambian wildlife orphanage to see if they use combinations of facial and gestural signals to convey complex meanings. Humans can knit together smaller elements of meaning according to known rules to form composites, which gives us the ability to communicate an infinite number of messages.
Sandler offers the example of “train station,” which we know is a station for trains because of the words and rules we know apply in English. She has also studied the expression of extreme emotion in athletes who have won and lost a competition. Taking her studies together, she concludes that humans are “compositional communicators.'”

Comment: It is not surprising that, as we are descended for earlier primates, we use hand signals as they do with the same parts of the brain involved. Still we speak words and they don't. We differ in spoken language and consciousness and that is a giant leap in evolution, which to my mind proves God exists as the source of that specialness.