How are ages sorted? The Western concept of childhood developed with the Industrial Revolution and the societal changes it brought. The new social order required people to work outside the home, and...

How are ages sorted? The Western concept of childhood developed with the Industrial Revolution and the societal changes it brought. The new social order required people to work outside the home, and schooling was required to socialize young people into the world of work. This socialization was different by gender; boys were prepared for factory work, girls for work in the home. As labor became more specialized, children needed more training and began to go to high school, creating a new life stage, adolescence. Young adulthood is a transitional stage, marked by milestones such as establishing a household, having a full-time job, getting married, completing education, and having children. Middle-aged individuals are dealing with changes in workplace and parenting status. Many middle-aged people are in the sandwich generation, caring for children and parents simultaneously. Currently, the fastest-growing segment of the U.S. population is among those in old age, a situation referred to as the “graying of America.”