Although we are taught the benefits of kindness and altruism, it seems we are happiest when simply told to pursue our own self-interest.
Researchers found the key to contentment is feeling we have no choice but to be selfish.
In contrast, the study, carried out by psychologists at the University of Pennsylvania, found that those who actively choose a selfish path usually have to battle with guilt.
They speculated that because we're taught as children that 'sharing means caring', if we make a decision out of self-interest, we often feel bad for prioritising ourselves over others.
But that frequently means we forego the things we know will make us happy.
That's odd, why would being unselfish not make us happy?