CHAPTER 1 INTRODUCTION TO AGING AND OLDER ADULTHOOD CHAPTER SUMMARY Chapter 1 is divided into five main sections. The first section provides some background information on the interest people have always had in the aging process, mainly how to retard it. It reviews how the scientific study of aging got started, giving dates when the Gerontological Society of America was founded (1945), when Division 20 (Adult Development and Aging) of the American Psychological Association had its beginnings (1945), and when the National Institute on Aging was established within the National Institutes of Health (1974). The terms geriatrics and gerontology are defined, followed by an explanation of why the scientific study of aging began so much later than the study of child development. One reason was an early belief that people develop to the point of maturity and then simply decline from their peak. Another reason was that in earlier times, only a small proportion of people lived into older adulthood. Today, the study of aging stems from scientific, personal, and practical concerns. The second section of the chapter explains how age can be defined in various ways – chronological, biological, functional, psychological, and social. How individuals identify their own age group membership can be subjective, as indicated by studies that find chronologically middle-aged and older adults often consider themselves younger than they really are. The chronological age of 65 is usually identified with entry into older adulthood, most likely a legacy of the United States Social Security system. However, throughout the book, older adulthood is divided into three categories: young-old (ages 65–74), old-old (ages 75–84), and oldest-old (ages 85+). We use many different terms to refer to people ages 65+, some of which older adults themselves consider more favorable than others. Ageism refers to discriminatory attitudes toward older adults. However, research studies on stereotypes about older adults often find that there are multiple stereotypes, some negative and some positive. The third section of the chapter covers demographic information about older adults both globally and in the United States. Both the number and proportion of older Americans is growing and should be close to 20% nationally by the year 2030, or approximately 72 million people over the age of 65. The oldest-old (85+) are the most rapidly growi