Happiness strengthens your immune system
Do you know a grumpy person who always seems to be getting sick? That may be no coincidence: Research is now finding a link between happiness and a stronger immune system. In a 2003 experiment, 350 adults volunteered to get exposed to the common cold (don’t worry, they were well-compensated). Before exposure, researchers called them six times in two weeks and asked how much they had experienced nine positive emotions—such as feeling energetic, pleased, and calm—that day. After five days in quarantine, the participants with the most positive emotions were less likely to have developed a cold.