It is just after 5pm and I am nursing a cup of Earl Grey tea in the hangar-like Sainsbury’s supermarket at Fulham Wharf in west London.

We are around a dozen customers in the megastore’s café as the autumn evening draws in, and most of us are on our own. None looks likely to be getting better acquainted anytime soon, I decide, as Tracy Thorn’s melancholy tones echo out of the fuzzy PA system. But the supermarket would like us to — it has launched an experiment, Talking Tables, to tempt shoppers into conversation. At some, the mental health charity Mind is in charge, at others staff play host. But at some, like this one, it’s left to spontaneous interaction.