From using words to overthrowing regimes, shared awareness is necessary for people to coordinate. The cognitive scientist explains to Nature how it works. When Everyone Knows That Everyone Knows...: ...

We laugh at the same jokes (usually for the same reasons), blush at innuendo, bow to dictators (at least temporarily), all because of a sense of implicit understanding: ie, common knowledge. We ...

I don’t know about you, but ever since I can remember – from my early teens – I have been bemused about the endless rituals we humans perform; and even more so about what can and can’t be said about ...