LSAT Explanation PT 40, S1, Q5: Psychologist: There are theories that posit

LSAT Question Stem

Which one of the following is an assumption on which the psychologist's argument depends? 

Logical Reasoning Question Type

This is a Necessary Assumption question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The psychologist is arguing that since there are theories with different causal mechanisms that are more successful at predicting human behavior than Freudian theories, Freudian theories should be abandoned in favor of these other theories. The structure of the argument can be broken down as follows:

Premise: There are theories with different causal mechanisms than Freudian theories.

Premise: These other theories are more successful at predicting human behavior.

Conclusion: Freudian theories should be abandoned in favor of these other theories.

To make this argument more accessible, let's use an example. Imagine we have two weather forecasting models: Model A and Model B. Model A is based on older techniques, while Model B uses newer methods. If Model B consistently provides more accurate weather predictions, then we should abandon Model A in favor of Model B.

An "Evaluate" question for this argument would be: "Do the other theories provide a better overall understanding of human behavior than Freudian theories?"

Now, let's discuss the answer choices for the question, which is a Necessary Assumption question. We need to identify the assumption on which the psychologist's argument depends.

a) This answer choice is not necessary for the argument. Even if Freudian theories offered interesting suggestions that were proven true, they may still be less successful at predicting human behavior than the alternative theories. The argument doesn't depend on this assumption.

b) This is the correct answer choice. The psychologist's argument depends on the assumption that a theory with greater predictive success is scientifically preferable. If this wasn't the case, the conclusion that Freudian theories should be abandoned would not follow logically.

c) This answer choice is not necessary for the argument. Even if Freudian theories had some success in predicting human behavior, they may still be less successful than the competing theories. The argument doesn't depend on this assumption.

d) How the predictive success of a theory is measured is irrelevant to the conclusion. The conclusion would still hold even if the measurement did not involve considering other theories that attempt to explain the same phenomena.

e) This answer choice is not necessary for the argument. The psychologist does not need to establish that Freud's theory is impractical; only that other theories are preferable due to their superior ability to predict human behavior. The argument doesn't depend on this assumption.

In summary, the correct answer choice is (b), as the psychologist's argument depends on the assumption that a psychological theory with greater predictive success is scientifically preferable to another theory.