People in middle adulthood (40s through mid-60s) aim to find their life's work and contribute to the development of others by volunteering/mentoring/raising children, etc.

Adolescents (ages 12-18) experiment with and develop a sense of who they are and what roles they want to play.

As toddlers (ages 1-3 years) begin to explore their world, they learn that they can control their actions and act on the environment to get results.

Between birth and one year, infants are dependent on their caregivers; caregivers who are responsive and sensitive to their infant's needs help their baby to develop a sense of the world as a safe, predictable place.

Preschool children (ages 3-6 years) are capable of originating activities and asserting control over their world through social interactions and play.

After age 65, most people are attempting to assess their lives and make sense of life and the meaning of their contributions.