Answer:
Until the 1970s, psychologists tended to treat adulthood as a single developmental stage, with few or no distinctions made between the various periods that we pass through between adolescence and death. Present-day psychologists realize, however, that physical, cognitive, and emotional responses continue to develop throughout life, with corresponding changes in our social needs and desires. Thus the three stages of early adulthood, middle adulthood, and late adulthood each have their own physical, cognitive, and social challenges.
In this section, we will consider the development of our cognitive and physical aspects that occur during early adulthood and middle adulthood — roughly the ages between 25 and 45 and between 45 and 65, respectively. These stages represent a long period of time — longer, in fact, than any of the other developmental stages — and the bulk of our lives is spent in them. These are also the periods in which most of us make our most substantial contributions to society, by meeting two of Erik Erikson’s life challenges: we learn to give and receive love in a close, long-term relationship, and we develop an interest in guiding the development of the next generation, often by becoming parents.