The most compelling reason for studying the neuropsychology of aging is the fact that there are so many more people who are elderly. Worldwide average life expectancy has already increased more in the past 100 years than in the previous 2000 years, due mainly to public health advances which are consequently fueling a rapid population growth of the elderly. Gerontology (the study of aging) and Geriatrics (health care for the elderly) are expanding disciplines and will continue offering career and service opportunities to the increasing number people who are interested in answering the questions and addressing the problems of aging.