Abstract
OBJECTIVES: Life-span perspectives have long acknowledged that individual functioning is shaped by historical and sociocultural contexts. Secular increases favoring recent cohorts are widely documented. However, little is known about secular trends in day-to-day activities and whether historical changes have occurred in younger and older adults alike. METHODS: We compared data from 2 independent cohort samples of the daily diary portion of the Midlife in the United States Study obtained 18 years apart (1995/1996 cohort: n = 1,499 vs 2013/2014 cohort: n = 782) and identified case-matched cohorts (n = 757 per cohort) based on age, gender, education, and race. An activity diversity score was calculated based on 7 common daily activities, using Shannon's entropy method. We additionally examined the roles of age and other sociodemographic and health characteristics in cohort differences in activity diversity. RESULTS: Results revealed that the 2013/2014 cohort experienced lower daily activity diversity than the 1995/1996 cohort. Age was positively associated with activity diversity in the 1995/1996 cohort, whereas age was negatively associated with activity diversity in the 2013/2014 cohort. These associations were significant for those who were older than age 55. Cohorts also differed in the types of most dominant activities and average time spent on those activities. DISCUSSION: Findings show changes in the lifestyles and daily activities of U.S. adults across 2 decades. Contrasting to the common belief that today's adults may be healthier and more active, they seem engaging in less diverse daily activities, which can be a risk for future health outcomes.