We use language to work successfully together; but of course we also know from everyday experience that joint activity does not necessarily lead to success. Two heads may be better sometimes, but we also say that ‘too many cooks spoil the broth’. That is, we find that people frequently misunderstand each other, and that joint activity can generate confusion, stifle individual creativity and achieve only
mediocrity. Studying how we normally use language to think together may help us to understand how effective collaboration can be more reliably achieved.