A researcher studying drug addicts found that, on average, they tend to manipulate other people a great deal more than nonaddicts do. The researcher concluded that people who frequently manipulate other people are likely to become addicts.

Which of the following, if true, most seriously weakens the researcher’s conclusion?


(A) After becoming addicted to drugs, drug addicts learn to manipulate other people as a way of obtaining drugs.
(B) When they are imprisoned, drug addicts often use their ability to manipulate other people to obtain better living conditions.
(C) Some nonaddicts manipulate other people more than some addicts do.
(D) People who are likely to become addicts exhibit unusual behavior patterns other than frequent manipulation of other people.
(E) The addicts that the researcher studied were often unsuccessful in obtaining what they wanted when they manipulated other people.

+1 for A, A is directly opp. to what is mentioned.

Why is the answer not D? In the given case, the author concludes that manipulative behavior causes people to become addicts. Thus, A causes B. The CR bible says that if we can show that there are other factors at play that cause B, and A is not the only one, then it undermines or weakens the argument. The choice D tells us that manipulative behavior is the not the sole reason for people becoming addict, i.e. A alone is not responsible for the cause of B. Can't we take such a reasoning to say that D indeed is the correct choice?
Help appreciated.
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Yes, the answer is 100% A

This argument is the typical correlation causation problem we see with many CR questions. Researchers have found a high incidence of those who manipulate others within drug addicts. They conclude that it is the manipulation that leads people to become drug addicts.

To weaken the argument, we can:

1) Remove the manipulation and show that people are still drug addicts

2) Give an alternate cause for drug addiction, or

3) Show that drug addiction leads to manipulation

The only answer choice that clearly does any of the above, is A.

Choice D, as many people who posted above me said, does not specifically attack the argument. It is a very weak attempt at weakening the argument...

A researcher studying drug addicts found that, on average, they tend to manipulate other people a great deal more than nonaddicts do. The researcher concluded that people who frequently manipulate other people are likely to become addicts.

Which of the following, if true, most seriously weakens the researcher’s conclusion?


(A) After becoming addicted to drugs, drug addicts learn to manipulate other people as a way of obtaining drugs. Drug addicts learn to manipulate other people after becoming addicted to drugs. This weakens the the argument. Correct
(B) When they are imprisoned, drug addicts often use their ability to manipulate other people to obtain better living conditions. Irrevelent
(C) Some nonaddicts manipulate other people more than some addicts do. The stimulus is talking about the entire group not some people from the group, Incorrecr
(D) People who are likely to become addicts exhibit unusual behavior patterns other than frequent manipulation of other people. Incorrect, Does not weaken the argument.
(E) The addicts that the researcher studied were often unsuccessful in obtaining what they wanted when they manipulated other people. Incorrect, Does not weaken the argument

People who manipulate -> Other people become addicts
Cause -> Effect

Only in A, this is reversed.
When they were addict, they learnt how to manipulate

(A) After becoming addicted to drugs, drug addicts learn to manipulate other people as a way of obtaining drugs.
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so it is between a and d.

Option a is clearly the opposite of the conclusion drawn in the argument.

Option D doesn't really weaken the argument as much as option A does. Notice the wording of option D. it says --> People who are likely to become addicts exhibit unusual behaviour patterns other than frequent manipulation of other people...this means that not so frequent manipulation can still be a cause. if anything, this option can strengthen the argument, slightly.

Hence the answer choice A is the correct answer

Premise: DA-->Manipulate people
Conclusion If someone Manipulates people--> likely to be drug addict

Only A breaks the conclusion by saying that drug addicts learn manipulation only after they become addicts. Hence A
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Here, "other than" means "outside of." It is possible that the people referred to in (D) display only these additional "unusual behavior patterns," or that they both frequently manipulate others and display other unusual behavior patterns.

Let's say that the "unusual behavior pattern" in (D) is excessive nose picking. (D) tells us that people who are likely to become addicts are DEFINITELY excessive nose pickers. However, (D) does NOT tell us whether these likely addicts frequently manipulate other people -- maybe they do, and maybe they do not. In other words, the information in (D) does not exclude the possibility that people who are likely to become addicts frequently manipulate others.

Because (D) does not give us any relevant information pertaining to the conclusion in the passage ("people who frequently manipulate other people are likely to become addicts"), it does not weaken that conclusion.

I hope that helps!
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