Subjective well-being is increasingly being used as an indicator of social progress, and some countries have begun to establish national surveys of well-being. Evidence suggests that positive affective states are associated with longer life expectancy and reduced risk of disease in old age. To date, research on the relationship between mortality and positive emotions has relied primarily on recall, where people are asked to rate their emotional state without any time frame or over a specific time period. Psychological studies have found that recall may deviate from reality because of possible errors in recall, the occurrence of recall bias, fantasy, and some salient memories. Such deviations of memory from reality may play an important role in the life course, as the past can have an impact on future behavior. To overcome the limitations of recall, methods such as ecologicalmomentary assessment (EMA), one-day reconstruction, or one or more tests of recall have been used to assess past emotions. involves the collection of a person’s feelings over a period of time, allowing for changes in mood over time. Using this method, Andrew Steptoe and Jane Wardle of the School of Epidemiology and Public Health at the University of London assessed the mood of 3,853 older people in the UK between the ages of 52 and 79, and followed them for five years. Cox proportional risk regression analysis showed that the hazard ratio for high positive mood to low positive mood was 0.498, which was reduced to 0.646 after controlling for age, gender, health factors and health behaviors. This result emphasizes the importance of promoting happiness in older adults.