Get up, have a productive day, get a lot done, laugh much, and smile more often (even when you don't feel like it). For, in the end, it is evident that happy people live longer (and healthier) than grumpy or stressed out folks.

Happiness does not heal, but happiness protects against falling ill. As a result, happy people live longer. The size of the effect on longevity is comparable to that of smoking or not.

One of the mechanisms behind that effect seems to be that chronic unhappiness causes stress, which on its turn reduces immune response.

Another possible mechanism is that happiness adds to the chance of adopting a healthy life style.

An implication of this finding is that public health can also be promoted by policies that aim at greater happiness for a greater number.