Mal Fletcher comments on Jonathan Dunne's Tube Chat campaign.

Tube trains are often over-crowded spaces, too, where people just want to be left to themselves. Because people don't normally chat on the Tube, we can grab a precious few minutes of downtime with a book, a newspaper or our favourite music.

On its best days - that is, when stations and carriages are not bursting at the seams and unconditioned air isn't stiflingly hot - the Tube offers an opportunity for us to catch our breath between engagements or commitments.

Understandably, people want to guard that time jealousy, preferring to remain as anonymous as possible.

This is not to say that journeys can't be made more interesting through conversation. In more than 30 years of global travel, I've had the privilege of meeting some fascinating individuals on planes, for example.

A short conversation with the Crown Prince of Denmark and his then fiancé on one long-haul flight was welcome, especially as I was living in Copenhagen at the time. Other chats with leaders in business, science and media have also been rewarding, at least for me (I can't speak for my partners in conversation!).

However, those conversations tended to evolve quite organically. Yes, someone took the initiative to kick-start the dialogue, but the talk flowed naturally, without feeling forced.

Wearing a badge to suggest the possibility of a conversation comes across as unnatural; it says: "Hey, talk to me, it's my cause, a campaign I'm on."

Encouraging conversation is a great thing, but I wonder whether the venue is wrong. Perhaps the modern office needs it more. Most workspaces desperately need to see a humanisation of a heavily digital environment.

Major companies such as the Bank of America have recently reorganised their lunch and coffee breaks because internal studies have shown that their most productive team members are those who mingle the most.

People need human contact in order to be productive and to find meaning in their work. Perhaps an Office Chat campaign would be more effective and helpful - and more culturally acceptable. Dear Mr. Dunne, have you considered...