Honesty is often said to be the best policy in social situations but being yourself at work is not a good idea for your career, research suggests.
While revealing your true character to a partner or friends is likely to make you happier, experts claim doing so at the office is not a recipe for promotion.
Scientists assessed levels of "authentic self expression" in 533 volunteers to see how far they opened up to people they interacted with socially.
The results showed that participants were more likely to "be themselves" with partners, followed by friends and then parents. However, they were much less likely to show their true self to work colleagues.
Those who opened up to their partners tended to have greater well-being and were more satisfied with life. But the same benefits were not seen from being authentic at work.
Dr Oliver Robinson, from the University of Greenwich in London, said: "You hear self-help gurus say that the secret of happiness is 'being yourself' or 'expressing your true feelings', but that doesn't seem to apply in the workplace.
"So in some circumstances, it may be that a polite smile or tactfully keeping quiet may be more conducive to your well-being than saying what you actually think and feel to work colleagues."
The results were presented at the annual meeting of the British Psychological Society, taking place in London.