Mounting evidence suggests that __________ is a major contributor to SIDS.

Correct Answer: A

Rationale: Impaired brain functioning is a major contributor to Sudden Infant Death Syndrome (SIDS). Research has shown that abnormalities in the brainstem, which controls automatic functions like breathing and heart rate, can play a role in SIDS cases. As such, mounting evidence suggests that compromised brain functioning is a significant factor in the occurrence of SIDS. Choices B, C, and D are incorrect. Higher-than-average birth weight, organized and patterned sleep behavior, and a family history of chromosomal abnormalities are not identified as major contributors to SIDS according to the provided information.

Correct Answer: C

Rationale: Three-month-old Jefferson will likely listen longer to human speech compared to nonspeech sounds because infants have a natural preference for speech sounds. This preference is believed to be attributed to their biological readiness to learn language and communicate with others. Choice A is incorrect because voices are a form of human speech, which is preferred over pure tones. Choice B is incorrect as noises do not necessarily engage infants' attention as effectively as human speech. Choice D is incorrect because Jefferson is more likely to listen longer to his native language rather than a foreign language at this early age.

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: Theorists who emphasize plasticity believe that change in response to influential experiences is possible. They argue that individuals have the capacity to adapt and change their behavior based on their experiences, rather than being limited by genetic predispositions or early childhood experiences. This perspective highlights the importance of environmental influences in shaping behavior and development. Choices B, C, and D are incorrect because they do not align with the concept of plasticity, which emphasizes the flexibility and adaptability of individuals in response to their experiences, rather than being fixed by heredity, childhood traits, or early experiences.

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.