Do you see the glass as half-full or half-empty? Optimism, it appears, isn't merely a crucial ingredient to happiness in life. According to numerous studies, having a positive personality is linked to several proven benefits. Here are the many reasons to smile!

#1 reason to smile!

Optimists are healthier.

Several studies have linked a pessimistic outlook in life with higher rates of infectious disease, poor health and earlier mortality. Researchers believe this could be related to a weakened immune system during times of stress: In the study "Optimism is Associated with Mood, Coping, and Immune Change in Response to Stress", it is found that when healthy people are subjected to stress, optimists tend to have better immune systems than negative thinkers.