This question presents an Assertion and a Reason related to elderly care and dementia. We need to evaluate the correctness of both statements.

Assertion (A) Analysis

Assertion (A) states: "When the elderly are not cared for by their children they develop early dementia."

• Dementia is a complex condition influenced by various factors like genetics, lifestyle, cardiovascular health, and social engagement.
• While lack of social support can negatively impact well-being, it is not the sole or direct cause of dementia. Elderly individuals may receive care from sources other than their children.
• Therefore, this statement is an oversimplification and considered incorrect.

Reason (R) Analysis

Reason (R) states: "Caring for the aged leads to a greater sense of well being and this prevents onset of dementia."

• The first part, that caring leads to a sense of well-being, can be true for both the caregiver and the recipient, fostering social connection.
• However, the claim that this "prevents onset of dementia" is too strong. While a positive sense of well-being and social engagement are considered protective factors against cognitive decline, they do not guarantee prevention.
• Dementia is multifactorial, and prevention is not solely dependent on well-being.
• Thus, this statement is also considered incorrect.

Conclusion

Both the Assertion (A) and the Reason (R) present inaccurate or overly strong claims regarding the relationship between elderly care and the onset of dementia. Consequently, both statements are incorrect.