Kindness not only makes life sweeter, it may make it longer, according to American researchers. Stephanie Brown, PhD, asked 423 older couples if they had helped a friend or neighbour just once in the previous year. Five years later, those who had were 50% more likely to outlive those who hadn't.

"Research has show that social contact is good for us, but we always assumed the benefits came from being on the receiving end," says Brown. "It turns out that the benefits may actually be roted in the contributions we make." We're not talking about donating a kidney here -- simply giving a friend a life could offer the life-lengthening benefits.