In developmental psychology, it has been concluded that in general, there is a(n) ______ during middle adulthood.

• A. complete stagnation in emotional development
• B. sudden decline in cognitive abilities
• C. peak in physical strength
• D. increase in crystallized intelligence

Answer: (D)

Verified step by step guidance

1. Understand the key terms involved: 'crystallized intelligence' refers to the accumulation of knowledge, facts, and skills that are acquired throughout life, while 'fluid intelligence' involves the ability to solve new problems and think abstractly.
2. Recognize that developmental psychology studies changes in cognitive, emotional, and physical abilities across the lifespan, including middle adulthood (roughly ages 40-65).
3. Recall that during middle adulthood, physical strength generally begins to decline rather than peak, so 'peak in physical strength' is unlikely to be correct.
4. Consider cognitive changes: fluid intelligence tends to decline with age, but crystallized intelligence typically increases or remains stable, reflecting accumulated experience and knowledge.
5. Conclude that the most accurate statement is that there is an 'increase in crystallized intelligence' during middle adulthood, as this aligns with research findings in developmental psychology.