Biological Aspects of Growth and Change

In the chapter, we will learn about possible reasons why people age and explanations for how long they live, including genetics, lifestyle, environmental factors, and culture. While the chapter does not provide a conclusive combined theory of why we age, we will briefly describe a number of theories of aging, some of which have increasing evidence of support. This discussion is followed by descriptions of life expectancy, longevity, and blue zones, as well as cross-cultural research about these topics. Finally, we briefly discuss some general biological changes as we age, primarily the changes in our sensory system (other biological changes are presented in Chapter 5 ), followed by an exploration of the interaction between context and culture on the perception of biological changes.