Michael Rosen and linguist Dr Laura Wright discuss how well we judge taking it in turns when we're in conversation. Professor Stephen Levinson has new research on the science behind this, and joins them in the studio for a carefully-calibrated discussion.. He believes that the back-and-forth pattern we instinctively fall into may have evolved before language itself. Levinson's research has found that it takes about 200 milliseconds for us to reply to each other, but it takes about 600 milliseconds to prepare what we're going to say - so we're preparing as we listen. Levinson notes that this is a pattern found across all human languages, and some animal species, and that infants begin taking turns in interactions at about six months of age, before they can even speak. But what's going on when someone seems to get it wrong, to interrupt or talk over the other person?