Overly optimistic expectations for the future can be hazardous to older people's health, a long-term study suggests.
Researchers from the University of Erlangen-Nuremberg in Germany, along with scientists from Berlin and Zurich, found older people who saw a darker future for themselves tended to live more healthily and longer than those who were more optimistic.
The results contradicted earlier studies finding that optimists lived longer.
"Pessimistic expectations of the future may encourage seniors to pay better attention to their health and protect themselves against dangers,'' said Frieder Lang, director of the Institute of Psychogerontology at the University of Erlangen-Nuremberg.
Researchers analysed survey data that had been gathered between 1993 and 2003 from more than 10,000 participants, who had been asked each year to rate both their current life satisfaction and expected life satisfaction in five years.
Dividing the participants into the age groups 18 to 39 years, 40 to 64 years, and 65 years and older, the researchers compared their actual life satisfaction with the expected one across six five-year intervals.
Researchers were struck by their finding that participants who overestimated future life satisfaction had an approximately 10 per cent increase in the risk of death or disability during the survey period.
The older the participants, the more pessimistically they saw their future. The young adults typically had overly optimistic expectations. The middle-aged adults were largely realistic.
"What surprised us was that the stabler the health and the higher the income of those surveyed, the more pessimistically they saw their future,'' Lang remarked.
He said this might be because they were more acutely aware of their mortality and more mindful of preserving what they had than hopeful of future improvement.
Results of the study were published online in the quarterly journal Psychology and Aging, published by the American Psychological Association.