Final answer:
Adults between 60 and 90 with higher education levels experience less cognitive decline, though reaction times slow and risk of illness increases. Crystallized intelligence typically remains stable or improves, while fluid intelligence begins to decline in late adulthood. Engaging in stimulating activities can delay cognitive decline, and pursuing meaningful activities and social connections can support healthier aging.
Step-by-step explanation:
Between ages 60 and 90, adults with higher levels of education show significantly less decline of cognitive abilities. Reaction time increases for older adults as processing speed slows. Loss of brain cells occurs, but they are not as critical for cognitive functioning as was once believed. Physical activity decreases and risk of illness increases.
Unlike our physical abilities which peak in our mid-20s and then begin a decline, our cognitive abilities such as crystallized intelligence remain steady or may even improve with age. In contrast, our fluid intelligence, which includes information processing abilities, reasoning, and memory, tends to decline starting in late adulthood. To delay cognitive decline, engagement in mentally and physically stimulating activities is beneficial.
Most adults experience continued physical decline in stamina, strength, reflex times, and sensory abilities as they age. Diseases like Alzheimer's, which can cause severe cognitive impairments, become more common. Nonetheless, pursuing meaningful activities, maintaining social connections, and staying physically and mentally active can contribute to healthier aging.