What does your daily cup of coffee say about you?
28 January 2013 Last updated at 09:10 GMT
Sales of coffee - both in supermarkets and High Street coffee chains - have held up despite hard economic times.
A new book called Consumed: How Shopping Fed the Class System argues that our coffee consumption is inextricably linked to our identity.
The author of the book, Harry Wallop, says the old class system in which you were defined by where your money came from has been replaced by one based on how you spend it.
He took the Today programme's Evan Davis on a tour of some High Street coffee houses in London to explain his theory.
"I think the social anxieties now are on brands and companies; what you have in your kitchen cupboard, or where you buy your morning cup of coffee," Mr Wallop said.
"Supposedly we are all middle class, and if that is so, how do we distinguish ourselves from each other? And I think people do actually quite enjoy distinguishing themselves."
First broadcast on BBC Radio 4's Today Programme on Monday 28 January 2012.