b'AGING IN THE 21ST CENTURYfunctioning and longer lifespans. The geneticTackling Alzheimersassociation discoveries in the HRS to come willNo disease of aging is more feared, or more bur-likely shape the future of how we measure certaindensome, than dementia. With the aging of our traits (Singer 2011). The capacity of the longitudi- population, it looms ever larger. Congress and the nal HRS to adapt its measurement of traits (likeNational Institutes of Health have begun to act personality or physical functioning) in futureon the need for more research on this condition, waves makes it uniquely valuable to the study ofwith a significant increase in funding for the NIA. genetic contributions to human behavior.The HRS has been studying cognition for over The GWAS technology will foster studies oftwenty years and is responding to the national survivorship, longevity, and genetic determinantseffort by launching its Healthy Cognitive Aging of aging along with studies of complex diseaseProject (HCAP). Working with several of its inter-traits, physiological measures and functions,national partner studies, the HRS is spearheading biomarkers and physical performance, as well asa global study of dementia in older populations, behavioral phenotypes. Exploration of gene bygenerating population-representative estimates environment interactions in a variety of health,of prevalence, providing longitudinal data for social, and behavioral domains will be possible.epidemiologic investigation, and gauging its The longitudinal nature of the HRS greatlyimpact on individuals, families, and the health enhances both the power to detect genetic effectscare system. The new HCAP project will make and provides an important, under-studied oppor- HRS and international data even more valuable tunity to examine the genetic influence on thein understanding who is at risk for dementia and age-dependent changes in key health indicatorshow that risk can be reduced as people age. over time. The ultimate goal is to uncover genetic variations in a population that can be used as biomarkers of healthy aging and longevity.18'