Psychology: Developmental Psychology Defined

Developmental Psychology Defined

Developmental psychology is concerned with both physical and psychological changes throughout life—from conception until death. Although theorists differ in their identification of developmental stages and the ages at which they occur, the breakdown is usually similar to that shown in Table 1 .

TABLE 1

Stages in Life

Life Stage	Approximate Age
Prenatal stage
Conception	Formation of zygote
Germinal	Conception–week 2
Embryo Fetus	Week 2–week 8
Fetus	Week 8–birth
Postnatal stage
Infancy	Birth–2 years
Toddler	2–3 years
Early childhood	3–6 years
Middle childhood	6–13 years
Adolescence	13–20 years
Young adulthood	20–40 years
Middle adulthood	40–65 years
Late adulthood	65+ years