It's a typical urban routine: Sit on the subway, headphones in, fiddling with the smartphone to avoid eye contact with fellow passengers.
Now a new campaign called Talk to Me wants to break that habit and change London's image as one of the loneliest places in Britain.
"Talking to strangers is a social taboo," said David Blackwell, one of the project's co-ordinators. "It's something we're inordinately afraid of. Can you imagine how different a city would be if you could just open up to other people with no expectation that a stranger must want something from you?"
Blackwell and other volunteers are handing out badges with the message "Talk to me, I'll talk to you." It's an invitation to strike up a conversation with the wearer, anywhere – whether it's on the commute or waiting in line for coffee.
The crowdfunded project is motivated in part by a recent Sheffield University survey indicating that 30 per cent of people in the British capital feel isolated and uninvolved in their community, with an impact on their emotional and physical wellbeing.
Of course, the whole concept is opt-in: If you want to keep to yourself, Blackwell says, that's fine. Just don't pick up a badge.
The project isn't without critics. There are fears that wearing a badge could invite unwelcome attention or street harassment.
"In principle, I like it," said Susie Feltz, who was in line at a food stall in Camden Market. "But there's no way I would feel comfortable if my 20-year-old daughter was walking around with a badge giving creeps an excuse to talk to her. Young women get enough unsolicited attention as it is."
Campaign co-founder Polly Akhurst said that the badges come with advice to withdraw from any conversation that makes the wearer feel uncomfortable. Overall, the feedback has been overwhelmingly positive, she said.
The campaign says it has distributed around 3,500 badges through partner organizations and cafés so far, a modest beginning in a city of more than eight million people. The new charity, which has 25 volunteers, has been holding weekly Talk to Me socials across the city.
Those who are tongue-tied can use Talk to Me flashcards as icebreakers: Suggested topics of conversation range from "What do you think defines a Londoner?" to "Should you feel guilty when you spend lots of money on yourself?"
Will Laffan went to a social three months ago when he moved from Ireland to London on his own after attending university – and says he's been hooked since then.
"The atmosphere is just completely different when you talk there. The conversations have broadened my horizons," he said. "I used to have difficulties with communication in general but it's much easier for me now."
In August the charity is organizing the first official "Talk to Me Day" with flash mobs, social events and a picnic designed to break the silence and get Londoners chatting. The initiative has attracted more than £8,000 ($14,660) in funding through the online fundraising platform Kickstarter.
Organizers say they have already been contacted by people in Paris, Berlin, Seoul and some U.S. cities who would like to start similar projects.
"The only problem we've had so far is that once people start talking, it can be difficult to get them to stop," Akhurst said.