Although great diversity characterizes the interests and concerns of investigators who study development, they share a single goal: to identify __________.

Correct Answer: D

Rationale: The correct answer is D because investigators who study development aim to identify the factors that influence consistencies and transformations in people from conception to death. This goal encompasses various domains such as physical, cognitive, emotional, and social development, highlighting the comprehensive nature of developmental research. Choices A, B, and C are incorrect as they do not align with the overarching goal of developmental researchers, which is to understand the factors influencing individuals throughout their lifespan, rather than focusing solely on genetic factors, environmental factors related to disease, or abnormal development in specific age groups.

Correct Answer: A

Rationale: The corrected statement 'Paul learned to play the violin at a young age' provides an example of an age-graded influence. This is because learning to play the violin is a behavior that is typical or expected at a certain age, reflecting how age influences individuals' experiences and development. In contrast, choices B, C, and D do not directly relate to age-graded influences. Jack's enjoyment of hiking, Sarah's preference for reading mystery novels, and Alex's proficiency in mathematics are not inherently tied to age-related developmental influences.

Correct Answer: D

Rationale: The statement that baby boomers were labeled a narcissistic, indulged, 'me' generation aligns with the common perception of this generation in popular culture and media. Baby boomers, who were born between 1946 and 1964, have often been characterized in this way due to their reputation for self-centeredness and individualism. Choices A, B, and C are incorrect because they do not accurately reflect the typical perception of baby boomers in popular culture and media.

Correct Answer: B

Rationale: Arnold Gesell is generally regarded as the founder of the child study movement, emphasizing the importance of observing and documenting children's behaviors to understand their development. While he was a significant figure in child development research, he did not specifically write child-rearing books for parents, foreshadow lifespan research, or construct the first successful intelligence test. Choice A is incorrect as Gesell's focus was more on research rather than writing child-rearing books. Choice C is incorrect as Gesell's main contributions were in child development, not specifically in aging research. Choice D is incorrect as Gesell is not credited with constructing the first successful intelligence test.

Correct Answer: C

Rationale: According to psychosexual theory, developed by Sigmund Freud, how parents manage their child's sexual and aggressive drives in the first few years is crucial for healthy personality development. This theory suggests that personality development is heavily influenced by a child's experiences during early stages of development, particularly related to handling sexual and aggressive impulses. Choices A, B, and D are incorrect as they do not align with the core principles of psychosexual theory, which focuses on the importance of early childhood experiences, especially in the context of sexual and aggressive drives.