Objectives: Limited evidence exists regarding the reasons for secular changes in cognitive functioning over historical time. Thus, we examined potential explanatory factors for changes in cognitive speed, a central dimension of cognitive functioning.
Methods: Population-based data of middle-aged and older adults from Germany (N = 5443) was used with baseline participants from 2002 to 2014, comparing the time periods 2002-2014.
Results: Cognitive speed improved in middle-aged adults (40-65) and older adults (66+). In both age groups, increases were partly explained by education, employment status, volunteering status, routine activities, and physical functioning. Changes in education were more important in explaining increases in older than in middle-aged adults, whereas changes in health were more important for explaining increases in middle-aged adults.
Conclusions: Cognitive speed increased in both age groups over historical time. Education, employment, volunteering, routine activities, and health were all important in explaining these changes, but their importance differed between age groups.
Keywords: aging; cognitive functioning; cognitive performance; morbidity; trends.