Zeida: Dr. Ladlow, a research psychologist, has convincingly demonstrated that his theory about the determinants of ...
DerekJuly 3, 2014
Why not E
In Anson's argument he/she claims 'responsible psychologists always accept the possibility that new evidence will show that their theories are incorrect. '
The question stem asks what can be inferred.
Couldn't we infer that ' physiologists who accept the possibility that new evidence will show that their theories are incorrect are responsible? '
RP > ANE
~ANE > ~RP
It seems to make sense that we could infer option E, but why is this the wrong answer?
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This is a Must Be True question so our correct answer will be 100% supported by the passage.
Let's diagram the principle rule in Anson's response, i.e. "Responsible psychologists always accept the possibility that new evidence will show that their theories are incorrect."
PR: RP ==> APTI not APTI ==> not RP
Answer choice (E) states: "Psychologists who accept the possibility that new evidence will show that their theories are incorrect are responsible psychologists."
Let's diagram this.
(E): APTI ==> RP not RP ==> not APTI
This is the incorrect contrapositive of Anson's principle rule. Remember, don't just reverse!
We must always switch the variables AND negate to create the contrapositive. We cannot infer anything else from a necessary condition. Answer choice (E) has taken the necessary condition of Anson's principle rule, "APTI," and used it to prove "RP," the sufficient condition of Anson's principle rule. Therefore, answer choice (E) is not supported by the passage.
Answer choice (B) states, "Psychologists who can derive consistently accurate predictions about how rats will perform in a maze from their theories cannot responsibly conclude that those theories cannot be disproved." We know from the principle rule in Anson's response that those who are responsible psychologists will accept the possibility that new evidence will show them that their theories are incorrect. Likewise, the contrapositive tells us that if a psychologist does not accept the possibility that new evidence will show that their theories are incorrect, then they are not responsible. So, answer choice (B) must be true because a psychologist who derives consistently accurate predictions on how rats perform in a maze cannot responsibly conclude that those theories cannot be disproved; if he did, then he would not be a responsible psychologist.
Hope that helped! Please let us know if you have any other questions.
