Final answer:
Developmental failure is a characteristic of late adulthood, highlighting the physical and cognitive declines experienced during this stage of life.
Step-by-step explanation:
Characteristics of late adulthood, which begins after the age of 65, involve a variety of changes and challenges that individuals face. One characteristic of late adulthood is developmental failure, which refers to difficulties or declines in physical and cognitive functions that individuals may experience. Tasks and mastery are also relevant during this stage, as individuals might have to adapt to new roles or cope with the loss of certain abilities. However, developmental failure is more pertinent to the essence of the question, as it directly relates to the changes that can occur in terms of health and cognitive functions during late adulthood, such as decreased muscle strength, slower reaction times, and problems with memory. It's also a time when chronic illnesses such as heart disease, cancer, and diabetes are more common.