Final answer:
Expertise and practical problem-solving abilities improve significantly in middle adulthood. Cognitive abilities, including problem-solving skills, tend to hold steady or even improve throughout early and middle adulthood.
Step-by-step explanation:
Expertise and practical problem-solving abilities improve significantly in middle adulthood. Unlike physical abilities, which peak in our mid-20s and then decline, cognitive abilities, including problem-solving skills, tend to hold steady or even improve throughout early and middle adulthood. Our crystallized intelligence, which includes information and skills acquired through experience, tends to remain stable and may even increase with age. However, fluid intelligence, which includes information processing abilities and reasoning, may decline in late adulthood.