Older adults getting smarter, not more fit
Older populations are scoring better on cognitive tests than did people of the same age in the past, but the average physical health of older adults has declined, according to population researchers from the International Institute for Applied Systems Analysis.
"We think that these divergent results can be explained by changing lifestyles," says IIASA World Population Program researcher Nadia Steiber, DPhil, author of the study, which recently was published in PLOS ONE. "Life has become cognitively more demanding, with increasing use of communication and information technology also by older people, and people working longer in intellectually demanding jobs," adds Steiber, an assistant professor at the Department of Economic Sociology of the University of Vienna. "At the same time, we are seeing a decline in physical activity and rising levels of obesity."
Using survey data from Germany that measured cognitive processing speed, physical fitness and mental health in 2006 and again in 2012, Steiber found that cognitive test scores increased significantly within the six-year period (for men and women and at all ages, from 50 to 90 years), whereas physical functioning and mental health declined, especially for low-educated men aged 50 to 64 years. Previous studies have found older adults to be in increasingly good health—"younger" in many ways than previous generations at the same chronologic age—with physical and cognitive measures all showing improvement over time. The new study is the first to show divergent trends over time between cognitive and physical function, according to IIASA.
Another study from IIASA population researchers, published last week in the journal Intelligence found similar results, suggesting that older people have become smarter in England, too.
"On average, test scores of people aged 50+ today correspond to test scores from people four to eight years younger and tested six years earlier," says Valeria Bordone, PhD, a researcher at IIASA and the affiliated Wittgenstein Center for Demography and Global Human Capital.
The studies confirm the "Flynn effect," a trend in increasing performance in standard IQ tests from generation to generation. Changes in education levels in the population can explain part but not all of the effect, the research reveals.