And humans, in the same vein, have laughter. But not just laughter—we also use smiling, exaggerated body movements, awkward facial expressions (like winking), and a high-pitched, giddy “play scream.” All of these signals mean roughly the same thing: “We’re just playing.” This message allows us to coordinate safe social play with other humans, especially when we’re playing in ways that hint at or border on real danger.
