‘When you greet a stranger, look at his shoes.’ While reading Malcolm Gladwell’s Talking to Strangers, this line, from an obscure 1985 REM song, got stuck in my head. I’ve always wondered whether it’s about showing modesty or trying to discern someone’s temperament from their footwear; either way, it’s a nice imitation of the kind of vague aphorism one often hears about social interaction. Whatever it means, it’s likely that Gladwell would argue that almost any advice about dealing with people we don’t know is better than the strategies we use in reality – strategies that regularly lead to disaster.

Gladwell’s thesis in his new book is that there are three major errors we make when talking to strangers: the default to truth, where we automatically give others the benefit of the doubt, often setting ourselves up to become victims in the process; the assumption of transparency, where