When faced with a problem, Sydney starts with a hypothesis, deduces testable inferences, and isolates and combines variables to see which inferences are confirmed. Sydney is in Piaget's __________ stage of development.

Correct Answer: D

Rationale: Sydney's approach of starting with a hypothesis, deducing testable inferences, and isolating and combining variables to confirm inferences aligns with the characteristics of the formal operational stage in Piaget's theory of cognitive development. This stage typically emerges during adolescence and is characterized by advanced logical thinking, abstract reasoning, and the ability to think systematically about all possible outcomes of a problem. Choice A, sensorimotor, is incorrect as it pertains to the stage where infants learn through sensory experiences and motor actions. Choice B, preoperational, is incorrect as it involves egocentrism and lack of conservation. Choice C, concrete operational, is incorrect as it focuses on operational thought and logical reasoning in concrete contexts.

Correct Answer: C

Rationale: Observations of imprinting in animals, such as ducklings following the first moving object they see after hatching, led to the major concept of the critical period in human development. The critical period is a specific time frame during which an organism must experience certain stimuli to develop properly. This concept has been influential in understanding various aspects of human development, such as language acquisition and social attachment. Choices A, B, and D are incorrect. Adaptation refers to adjusting to the environment, equilibrium is about balance in cognitive processes, and classical conditioning is a learning process associated with behaviorism, none of which directly relate to the concept derived from imprinting observations.

Correct Answer: A

Rationale: Vygotsky's emphasis on culture and social experience did not lead him to neglect the biological side of development. Instead, he believed that biological factors and social influences interact to shape cognitive development. Choice A is correct because it reflects Vygotsky's view that biological factors and social experiences work together in cognitive development. Choices B, C, and D are incorrect as Vygotsky's emphasis was not on overemphasizing heredity, focusing solely on independent efforts of children, or placing too much emphasis on children's capacity to shape their own development.

Correct Answer: D

Rationale: In ecological systems theory, the chronosystem refers to the dimension of time and how events and transitions over time can influence an individual's development. Toby's move just before entering fourth grade represents a significant change in his life that falls under the chronosystem. The microsystem involves the immediate environments and relationships that directly influence an individual, the mesosystem relates to connections between these environments, and the exosystem includes external settings that indirectly influence the individual, such as parents' workplaces. Therefore, Toby's move best exemplifies a change in the chronosystem due to the temporal influence on his development.

Correct Answer: D

Rationale: The correct answer is D, the lifespan perspective. This perspective underscores the idea that individuals have the capacity for growth and change at any age, highlighting plasticity throughout the lifespan. It acknowledges the continuous development and adaptability of individuals to various experiences and factors. Choice A, the psychoanalytic perspective, focuses more on unconscious processes and early childhood experiences. Choice B, ethology, emphasizes the study of animal behavior in natural environments. Choice C, evolutionary developmental psychology, examines how evolutionary principles influence human development but does not specifically focus on plasticity at all ages.