Chapter 1: Important Fundamental Principles in Lifespan Development Overview I. Stages of Life A. The prenatal period through old age 1. Substantial changes occur throughout the entire lifespan. 2. A brief description of each of the periods used to characterize development is provided. These include prenatal period, infancy/toddlerhood, early childhood, middle childhood, adolescence, young adulthood, middle adulthood, and late adulthood/old age. 3. These stages are social constructions, so not all cultures agree on when a child becomes an adult, and our understanding/categorization of human development continues to change. 4. Although periods of life are a useful way to talk about most individuals in each stage, individual variability within stages can be immense because of unique genetic makeups and environmental influences. B. Aging processes 1. Biological aging processes refer to changes in how the human body functions across the lifespan. a. Anabolism is defined as the process of our bodies building up to their peak biological performance. b. Catabolism is defined as the inevitable slow deterioration of the human body following the attainment of peak potential. Catabolism cannot be reversed, but it can be slowed with appropriate strategies and lifestyle choices. 2. Psychological aging is an individual’s perception of his or her age. 3. Social aging is the way individuals view aging within their own culture or society. Perceptions are mediated by culture, vocation, and socioeconomic status. II. The Nature of Development A. Development is cumulative. 1. Development occurs continuously and builds upon itself. 2. To reach an optimal understanding of current development, individuals must be viewed in the context of their entire lifespan. B. Development is variable. 1. There is no set developmental trajectory that will make development exactly the same for any two individuals. 2. Once born, individuals follow in