one of my favorite books

"The first language humans had was gestures. There was nothing primitive about this language that flowed from people’s hands, nothing we say now that could not be said in the endless array of movements possible with the fine bones of the fingers and wrists. The gestures were complex and subtle, involving a delicacy of motion that has since been lost completely. 

During the Age of Silence, people communicated more, not less. Basic survival demanded that the hands were almost never still, and so it was only during sleep (and sometimes not even then) that people were not saying something or other. No distinction was made between the gestures of language and the gestures of life. The labor of building a house, say, or preparing a meal was no less an expression than making the sign for I love you or I feel serious. When a hand was used to shield one’s face when frightened by a loud noise something was being said, and when fingers were used to pick up what someone else had dropped something was being said; and even when the hands were at rest, that, too, was saying something. Naturally, there were misunderstandings. There were times when a finger might have been lifted to scratch a nose, and if casual eye contact was made with one’s lover just then, the lover might accidentally take it to be the gesture, not at all dissimilar, for Now I realize I was wrong to love you. These mistakes were heartbreaking. And yet, because people knew how easily they could happen, because they didn’t go round with the illusion that they understood perfectly the things other people said, they were used to interrupting each other to ask if they’d understood correctly. Sometimes these misunderstandings were even desirable, since they gave people a reason to say, Forgive me, I was only scratching my nose. Of course I know I’ve always been right to love you. Because of the frequency of these mistakes, over time the gesture for asking forgiveness evolved into the simplest form. Just to open your palm was to say: Forgive me."

"If at large gatherings or parties, or around people with whom you feel distant, your hands sometimes hang awkwardly at the ends of your arms – if you find yourself at a loss for what to do with them, overcome with sadness that comes when you recognize the foreignness of your own body – it’s because your hands remember a time when the division between mind and body, brain and heart, what’s inside and what’s outside, was so much less. It’s not that we’ve forgotten the language of gestures entirely. The habit of moving our hands while we speak is left over from it. Clapping, pointing, giving the thumbs-up, for example, is a way to remember how it feels to say nothing together. And at night, when it’s too dark to see, we find it necessary to gesture on each other’s bodies to make ourselves understood.” 
― Nicole Krauss, The History of Love