You stand facing each other, thirty meters apart. You don't know him—he's not a neighbor, not a relative, you've never heard of him from anyone. And you want to say one thing: I won't attack. There's nothing to say, you don't have a single word in common.

We'll explore how people negotiated without language: what's clear to anyone without training, and what's easy to understand. How they demonstrated that they wouldn't attack, who made contact first, and why it wasn't warriors. And most importantly, about silent exchange, a way of trading without meeting or saying a word, in which deception is technically possible, but unprofitable.

A shell from the seashore reached people who had never seen the sea.