Introduction to Human Development

Human development is the scientific study of patterns of change and continuity that happen throughout a person’s lifespan.

It consists of both positive and negative changes.

For example, learning to walk in early childhood reflects positive change, while reduced physical ability in later life may reflect negative change.

Together, these changes happen in an organized pattern across eight recognized stages, each defined by a specific age range.

First, the prenatal stage extends from conception to birth.

Next, infancy and toddlerhood span from birth to age three.

After that, early childhood includes ages three to six, followed by middle childhood from six to eleven.

Then, adolescence ranges from ages 12 to 18.

Following this is the emerging and young adulthood stage. It begins with emerging adulthood, from the late teens through the mid-twenties, and continues into young adulthood until around age forty.

Continuing the progression, middle adulthood extends from the early forties to sixty-five.

Finally, late adulthood begins at sixty-five and continues until the end of life.