Aging and Health Page 1 of 57 PRINTED FROM OXFORD HANDBOOKS ONLINE (www.oxfordhandbooks.com). (c) Oxford University Press, 2015. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Handbooks Online for personal use (for details see Privacy Policy). Subscriber: Hiroshima University; date: 11 April 2016 Aging and Health Karen S. Rook, Susan Turk Charles, and Jutta Heckhausen The Oxford Handbook of Health Psychology Edited by Howard S. Friedman Abstract and Keywords The biopsychosocial model of health views health and illness in old age as resulting not only from biological and physical factors but also from the cumulative effects of a lifetime of psychological, social, and behavioral processes. This model recognizes the biological trajectory of decline throughout the adult lifespan and the fact that physical changes increase older adults’ susceptibility to acute and chronic conditions. In addition, this model acknowledges that psychological and social processes interact over time with biological changes to influence physical functioning, onset and progression of disease, and adaptation to illness. The chapter is organized in three main sections. The first section emphasizes the biological component of the model, discussing trajectories of physical functioning and health in old age, including physical decline, morbidity, and mortality. The second section focuses on the psychosocial component of the biopsychosocial model, emphasizing psychosocial factors that influence physical health and functioning in old age. The chapter concludes by discussing two very different scenarios that researchers have projected for the health of future cohorts of older adults. Keywords: Older adults, elderly, biopsychosocial model, aging, health, life expectancy In the past century, economically developed nations experienced unprecedented changes in the age structure of their populations, as a result of improved public health measures and medical advances that extended life expectancy. Throughout human history, there have always been individuals who lived to an advanced age, but such survival was unusual before the 20th century. During the 20th century, life expectancy increased markedly and birth rates declined, ushering in an era of dramatic societal aging among developed nations. Since 1900, for example, the total population of the United States tripled in size, but the population of people over age 65 grew 12-fold (American Print Publication Date: Aug 2011 Subject: Psychology, Health Psychology Online Publication Date: Sep 2012 DOI: 10.1093/oxfordhb/9780195342819.013.0015 Oxford Handbooks Online