Final answer:
Evidence of declines in fluid intelligence as people age includes slower processing speed and reduced problem-solving abilities. Mental and physical activities can help delay cognitive decline. Lifestyle modifications and cognitive rehabilitation may also mitigate such decline.
Step-by-step explanation:
As people age and experience declines in fluid intelligence, the effects that provide evidence of this cognitive change include a slower processing speed. Fluid intelligence entails the ability to solve new problems, use logic in new situations, and identify patterns. Unlike crystallized intelligence, which may remain stable or improve as we age, fluid intelligence tends to decline, leading to slower information processing abilities, reasoning, and memory. This decline is evidenced by more errors and slower responses in cognitive tasks, as revealed in studies comparing older adults with younger individuals. Efforts to delay the onset of cognitive decline have been associated with engaging in mentally and physically stimulating activities. Such engagement has been shown to result in less cognitive decline and a reduced incidence of mild cognitive impairment and dementia. However, a variety of factors, including chronic health conditions and a less efficient immune system, contribute to the complexity of aging and cognitive health.
It is important to address lifestyle and environmental factors to potentially mitigate cognitive decline, with research suggesting strategies like cognitive rehabilitation, including the use of virtual reality technology, may be beneficial.