Answer: False - In fact, the older adult population is the most diverse or heterogeneous age group. Development consists of an interaction of the individual (with all of their genetic and biological make-up) and the context within which they live. The older an individual gets, the greater the impact of the context. In other words, your life experience serves to change you in unique ways; you experience different people and life events, you make choices, and you learn. As all of this is different for everyone, each of these life experiences serves to increase people's diversity across the life-span.
The only time older adults will demonstrate homogeneity is in response to disease. One should remember however that an individual suffering from Alzheimer's Disease at 77 will share similarities with another individual suffering from Alzheimer's Disease who is 34.