Critical life course events and experiences - in both youth and middle adulthood - may contribute to health and cognition in later life, says a new study.
Furthermore, the authors found that the processes of aging linked to cognition and those linked to health should be studied simultaneously, as part of the same set of processes.
There also is an emerging consensus that a multidisciplinary theoretical approach is necessary to understand the nature of the processes of cognitive aging.
"Knowledge of the relationship of aging to health and cognitive function is crucial to the understanding of the linkages between age-related socioeconomic, racial/ethnic, gender, and health disparities," state guest editors Duane F. Alwin, PhD, and Scott M. Hofer, PhD.
Among the issue's findings:
For many cognitive abilities, the declines associated with aging do not manifest themselves until after age 75.
High school class rank has a much larger effect than on survival than IQ across the lifespan.
The progressive substitution of mechanical power for human physical activity is undermining the physical fitness needed to preserve cognitive function.
Greater social contact and support are associated with better cognitive functioning, whereas greater conflict is associated with lower cognitive unctioning.
Diseases either caused by or associated with aging - particularly vascular changes - play a larger role in age-related cognitive changes than is often acknowledged.
The findings have been published in the Journals of Gerontology Series B: Psychological Sciences and Social Sciences.