According to Erikson's theory, which stage of social development is related to adulthood?

During young adulthood (18 - 40 years), takes place the intimacy versus isolation stage.

In this period, the major conflict centers on forming intimate, loving relationships with other people.

During middle adulthood (40 - 65 years), takes place the generativity versus stagnation stage.

People feel a need to create things that will outlast them, often creating positive changes that will benefit other people.