Want to be happier? First, work out if you’re an ‘upholder’ or a ‘rebel’

Happiness expert Gretchen Rubin says there are four basic personality types, and improving your life is all about working out whether you conform or rise up

In the often-woolly world of personal development, Gretchen Rubin is a practical and grounded sort. She doesn't even - shock - like meditation. Rubin has spent the past decade researching and writing about happiness. A former lawyer, it was her fifth book, The Happiness Project written in 2009 - for which she spent a year testing different theories about how to live a more fulfilled life - that became a bestseller and made her a star of the self-help world (she also runs a popular blog and podcast).

Her latest book, The Four Tendencies, develops ideas first explored in 2015's Better Than Before, in which she looked at how happiness and habits were linked. "[People] wanted to run," she says, "but for some reason they couldn't make themselves exercise. Or they wanted to write a novel in their free time, but somehow they weren't doing it. It was trying to figure out why people did and didn't break habits."