Final answer:
The observation that older adults often become nostalgic for the "good old days" reflects the self-image hypothesis, which states that people maintain a positive self-image throughout their lives.
Step-by-step explanation:
The observation that older adults often become nostalgic for the "good old days" reflects the self-image hypothesis. The self-image hypothesis states that people maintain a positive self-image throughout their lives. In the case of older adults, this positive self-image leads them to view the past more favorably and become nostalgic for a time when they felt younger and more capable.
The self-image hypothesis is supported by research such as Levy et al.'s study in 2002, which found that positive self-perceptions of aging were associated with increased longevity. Additionally, Logan, Ward, and Spitze's research in 1992 showed that older adults tend to define "old age" in terms of greater years than their current age.
In conclusion, nostalgia in older adults can be attributed to the self-image hypothesis, which states that people maintain a positive self-image throughout their lives.