Therapist: In a recent study, researchers measured how quickly 60 diff

Question

Therapist: In a recent study, researchers measured how quickly 60 different psychological problems waned as a large, diverse sample of people underwent weekly behavioral therapy sessions. About 75 percent of the 60 problems consistently cleared up within 50 weeks of therapy. This shows that 50 weekly behavioral therapy sessions are all that most people need.

The therapist’s argument is logically most vulnerable to criticism on the grounds that it

(A) takes for granted that there are no psychological problems that usually take significantly longer to clear up than the 60 psychological problems studied
(B) fails to address the possibility that any given one of the 60 psychological problems studied might afflict most people
(C) takes for granted that no one suffers from more than one of the 60 psychological problems studied
(D) fails to address the possibility that some forms of therapy have never been proven to be effective as treatments for psychological problems
(E) takes for granted that the sample of people studied did not have significantly more psychological problems, on average, than the population as a whole

Bunuel · Accepted Answer

EXPLANATION FROM Fox LSAT

There are 60 total psychological problems in the study. Seventy-five percent of the types of problems (not 75 percent of the  patients ) cleared up within 50 weeks of therapy. From this, the therapist concludes that 50 weeks of therapy is all that “most people” need. The problem with this logic is that a majority of people might have one type of problem, and that particular type of problem may or may not have been in the 75 percent that cleared up within 50 weeks. For example, suppose 75 percent of all people have major depression, and suppose that major depression takes 100 weeks to cure. (It’s part of the 25 percent of problems that did not clear up within 50 weeks of therapy.) If this is true, then there is no way it is true that “most people” need only 50 weeks. Quite the opposite! “Most people” in this scenario would require 100 weeks. That’s the flaw here.

A) The argument didn’t take for granted that there are no psychological problems that usually take longer to clear up than the 60 problems studied. It did take for granted that most people, or a significant number of people, might have other diseases, but that’s not what this answer says. The therapist simply didn’t take for granted that there are no other problems. If you think he did, you have to be able to put your finger on the page at exactly the point where he did it. I’m pretty sure you can’t.

B) Yep. The therapist made a conclusion about a proportion of people, when his evidence was about a proportion of diseases. He forgot that most people could have one disease, as in our depression example above.

C) He didn’t do this. Show me where he did it.

D) Who cares if some types of therapy are not proven to be effective? The argument isn’t even about types of therapy. This is irrelevant.

E) There is no reason given to believe that there was any problem with the sample. Answers about sample bias are very rarely correct unless the argument gives you a good reason to believe the sample is biased. Here, the argument even says that the sample was “large and diverse.” There’s no way this is the answer.

Our answer is B.

100mitra · Answer

Correct Option B

Premise : A recent study found that about 75% of 60 different psychological problems were cleared up with 50 weeks of therapy.
 Conclusion : 50 weekly behavioral therapy sessions are all that most people need.

Correct Option: B 
This focuses on the gap between the premise and the conclusion. 
There is a chance that most people are afflicted by an issue which takes longer than 50 weeks to cure, 
as only 75% of 60 issues were found to be cured with 50 weeks of therapy

Posted from my mobile device

sivatx2 · Answer

study weekly behavioral therapy ----> 60 psychological prob.
~45 problems solved in 50 weeks.
=> Most people need only 50 week therapy.
This assumes that those about 45 problems are the most common psychological problem people could experience.
That means to weaken this argument if we can prove that most people experience the other 15 psychological problem as a common issue, then it could be that people need more than 50 week of therapy. It could be that one of the 15 psychological problem may affect the most people which takes longer to cure.

(A) takes for granted that there are no psychological problems that usually take significantly longer to clear up than the 60 psychological problems studied 
 No, this is not the assumption of argument. Eliminate.

(B) fails to address the possibility that any given one of the 60 psychological problems studied might afflict most people 
 Yes, anyone from those other 15 can also be afflicting most people. Keep.

(C) takes for granted that no one suffers from more than one of the 60 psychological problems studied 
 Other problems outside the study is irrelevant, as the argument never stated there is no more than 60 problems. Eliminate

(D) fails to address the possibility that some forms of therapy have never been proven to be effective as treatments for psychological problems 
 The possibility that a therapy is ineffective is irrelevant to the argument. Eliminate

(E) takes for granted that the sample of people studied did not have significantly more psychological problems, on average, than the population as a whole 
 Large diverse sample of people was considered and doesn't require to have the entire population need to be studied. Eliminate

finisher009 · Answer

Analysis of the Argument
1. Evidence: A study of 60 different psychological problems found that 75% of these problems (45 of the 60 types) cleared up within 50 weeks of therapy.
2. Conclusion: Therefore, 50 weeks of therapy are enough for most people.
Identifying the Flaw

The core of the argument makes a classic GMAT reasoning error. It equates a percentage of the types of problems with a percentage of people.

The study tells us about the duration of 60 different conditions. It says nothing about how common each condition is. It’s possible that the 25% of problems (the 15 types) that take longer than 50 weeks to treat are extremely common (like major depression or anxiety), while the 75% that resolve quickly are very rare.
If the most widespread problems are the ones that take the longest to treat, then the conclusion that “most people” only need 50 sessions would be false, even though most types of problems are resolved by then.

Evaluating the Options
• (A) takes for granted that there are no psychological problems that usually take significantly longer to clear up than the 60 psychological problems studied. This is a potential weakness (sample limitation), but the primary flaw lies in how the conclusion is drawn from the existing evidence, not what evidence might be missing about other problems.
• (B) fails to address the possibility that any given one of the 60 psychological problems studied might afflict most people. This is the correct answer. It directly targets the flaw. If a very common problem is in the 25% group that takes longer than 50 weeks, the therapist’s conclusion about “most people” collapses.
• (C) takes for granted that no one suffers from more than one of the 60 psychological problems studied. The argument is about the general needs of “most people,” not the specific complexity of individuals with co-occurring conditions. This is a secondary issue.
• (D) fails to address the possibility that some forms of therapy have never been proven to be effective... This is out of scope. The argument is specifically about the effectiveness of the behavioral therapy used in the study.
• (E) takes for granted that the sample of people studied did not have significantly more psychological problems... The stimulus states the sample was “large” and “diverse,” suggesting it was representative. The flaw isn’t in the sample but in the interpretation of the results.

The correct answer is (B).

Therapist: In a recent study, researchers measured how quickly 60 diff

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

Therapist: In a recent study, researchers measured how quickly 60 diff

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards