Work and friendship don't mix, thought Katherine Hu. A recent graduate, she found it harder to form bonds with colleagues than she'd expected. But then she concluded that not having friends at work helps you set boundaries and remain professional. After all, work is fundamentally a financial transaction, right?

Well, we spend many of our waking hours at work - and the science suggests that if we decide not to use that time making meaningful friendships then our health and wellbeing could suffer.