The strongest links between positive emotions and health were found in studies that examined "trait" emotions, which reflect a person's typical emotional experience, rather than "state" emotions, which reflect momentary responses to events. People who typically report more positive emotions experience lower rates of chronic illness, symptoms and pain. Moreover, among the elderly who live on their own or with family rather than in retirement homes, positive emotional dispositions are linked to living longer. In contrast, positive emotions are not associated with increased longevity in studies of other populations, and though possibly beneficial for recovery from less serious diseases, extremely positive emotions are in some cases associated with poorer outcomes among those with serious illness.
"Overall, the literature suggests an association between positive emotions and some measures of good health, but there are many subtle weaknesses in these studies and it would be inappropriate to make any strong conclusions," Cohen said.
One problem in interpreting the literature is that in many cases, it is difficult to distinguish between the effects of positive and negative emotions. For example, do elderly living on their own or with family live longer because they are happy or because they are not sad? Interestingly, people's experiences of positive and negative emotions are partly independent in some circumstances. For instance, in
Contact: Jonathan Potts
Carnegie Mellon University