Correct Answer: D

Rationale: Studying identical twins raised in different environments allows researchers to understand the impact of genetics versus environmental factors on traits. Choice A is incorrect because differences in brain function can be influenced by a variety of factors and not solely by environmental differences. Choice B is incorrect as concordance rates tend to be higher in identical twins reared together due to shared genetics and environment. Choice C is incorrect because genetics do not change due to being raised in different environments.

Correct Answer: B

Rationale: Freud's major contribution to current perspectives of mental disorders is the concept of the unconscious and its influence on behavior. While the Oedipal complex (Choice A) and Electra complex (Choice C) are important psychoanalytic concepts introduced by Freud, they are more focused on childhood psychosexual development rather than mental disorders. The understanding of the three structures of personality (Choice D) refers to Freud's id, ego, and superego model, which is essential in psychoanalytic theory but not specifically related to mental disorders.

Correct Answer: D

Rationale: Genes determine the range of characteristics a person has. Choice A is incorrect because genes do not solely determine behavior, as behavior is influenced by a combination of genetic and environmental factors. Choice B is incorrect because while genes can contribute to the risk of developing mental disorders, they do not directly cause them. Choice C is incorrect as genes contribute to but do not solely determine all characteristics a person will have.

Correct Answer: B

Rationale: The correct answer is B. Childhood experiences, such as trauma and attachment issues, can indeed have a profound impact on adult psychopathology. These experiences can shape an individual's psychological development, influencing their mental health and well-being throughout their life. Choice A is incorrect as research shows that childhood experiences do play a significant role in adult psychopathology. Choice C is also incorrect as there is evidence supporting the link between childhood experiences and adult psychopathology. Choice D is incorrect because childhood experiences can have more than just a minimal impact on adult psychopathology; they can be quite substantial.

Correct Answer: C

Rationale: Freud's psychosexual stage that occurs between the ages of 3 and 5 is the phallic stage. During this stage, children focus on the genitals and start to identify with the same-sex parent while developing the superego. Choice A, the oral stage, occurs during infancy (0-1 year), where gratification is centered around the mouth. Choice B, the anal stage, occurs between the ages of 1 and 3, focusing on toilet training. Choice D, the genital stage, is the final stage in Freud's theory, occurring from puberty onwards, where the focus is on mature sexual relationships.