Life in Six Acts
1 Infancy
In its first year, a baby’s brain doubles in size. By the end of infancy, it has reached 80% of the size of the adult brain. “Change is probably the single best word to describe infancy,” says Santiago Morales, assistant professor of psychology and pediatrics.
2 Childhood
Between ages 3 and 6, self-regulation takes shape, and this coincides with the important development of children’s ability to understand others’ thoughts and feelings, says Morales.
3 Adolescence
Adolescence as distinct from adulthood is a relatively modern concept. “The United States mandated high school attendance in 1918, cementing the teen years as a cultural category that would blossom during the 20th century,” says Professor Emeritus of Sociology Michael Messner.
“Characterizing life as a series of stages offers a way to describe how psychological demands and opportunities evolve over the lifespan — from how we manage relationships with others to how we gain in resilience and wisdom.”
4 Young Adult
After high school, life’s dress rehearsal concludes. College, careers and longer-term relationships — often romantic — begin. “In young adulthood, we start to find our place in the world,” says Professor Emerita of Psychology and Pediatrics Gayla Margolin.
5 Middle Age
“This is a stage of increased responsibilities at home and at work — along with a fair share of economic stress,” says Margaret Gatz, professor of psychology. But there’s good news: Research shows that around age 50, self-reported happiness tends to rise.
6 Old Age
With age comes wisdom — and a chance to share it. “Mentoring increases our sense of purpose in life, and that’s associated with decreased cognitive decline and dementia risk,” says Duke Han, professor of psychology and family medicine.
