A study published in the Journal of Psychosomatic research found that people with an optimistic spouse had better physical functioning and fewer chronic illnesses than people with a more pessimistic partner.
Researchers tracked 2000 couples over age 50 for 4 years and collected data on physical functioning, self-rated health and chronic illnesses (and presumably levels of optimism / pessimism, although it doesn’t say in the article). Data analysis showed that individual and a spouse’s optimism both predicted better health (self rated) and physical functioning.
Practically speaking, an optimistic spouse would encourage his / her partner to get more exercise and eat healthier meals because they genuinely believe the behaviour will make a difference to health.
Compared with pessimists, optimistic people are more likely to have stronger networks of social support, to have more satisfaction in close relationships and to be better at cooperative problem solving – all factors that may help explain the findings.