“When we talk we take turns, where the ‘right’ to speak flips back and forth between partners. This conversational pitter-patter is so familiar and seemingly unremarkable that we rarely remark on it. But consider the timing: on average, each turn lasts for around 2 seconds, and the typical gap between them is just 200 milliseconds—barely enough time to utter a syllable. That figure is nigh-universal. It exists across cultures, with only slight variations. It’s even there in sign language conversations.”