Bunuel
Weight loss can be accomplished through dietary changes or through use of a supplement made from the root of a common plant. It has been found that people who use the supplement to lose weight are more prone to panic attacks than people who lose weight through dietary changes only. Clearly, the supplement causes panic attacks.
The argument is most vulnerable to criticism on which of the following grounds?
A. It fails to consider the possibility that weight loss itself causes an increase in tendency to have panic attacks.
B. Without clear evidence, it rules out the possibility that panic attacks cause people to lose weight.
C. It assumes without warrant that dietary changes cannot cause a reduction in the tendency to have panic attacks.
D. It overlooks the possibility that people who use the supplement to lose weight also use dietary changes.
E. It assumes without warrant that those most likely to have panic attacks choose to use the supplement rather than dietary changes to lose weight.
Target Test Prep Official Explanation:This argument has a cause-and-effect conclusion, which is that “the supplement causes panic attacks.”
The support for that conclusion is that It has been found that people who use the supplement to lose weight are more prone to panic attacks than people who lose weight through dietary changes.
The correct answer will highlight a flaw in the way the author has arrived at the conclusion.
(A) It fails to consider the possibility that weight loss itself causes an increase in tendency to have panic attacks.The author bases the conclusion on a comparison. The people who use the supplement to lose weight are more prone to panic attacks than people who lose weight through dietary changes.
So, even if it is the case that weight loss itself causes an increase in tendency to have panic attacks, we still have the fact that people are more prone to panic attacks when they use the supplement to support the conclusion that the supplement causes panic attacks.
So, the argument works regardless of whether it considers the possibility that weight loss itself causes an increase in tendency to have panic attacks since that existence or nonexistence of that possibility doesn’t affect the strength of the argument.
(B) Without clear evidence, it rules out the possibility that panic attacks cause people to lose weight.Notice that the author bases the conclusion on a comparison. The people who use the supplement to lose weight are more prone to panic attacks than people who lose weight through dietary changes. So, everyone is losing weight, but the people who use the supplement have more panic attacks.
Thus, even if panic attacks do cause people to lose weight, it is still the case that people who use the supplement are MORE prone to panic attacks. So, the author doesn’t have to have done what this choice says in making the argument. Even without ruling out the possibility that panic attacks cause people to lose weight, the author could still make the same argument.
(C) It assumes without warrant that dietary changes cannot cause a reduction in the tendency to have panic attacks.
Correct AnswerThe author bases the conclusion on a comparison. The people who use the supplement to lose weight are more prone to panic attacks than people who lose weight through dietary changes.
Because of that difference in outcomes, the author concludes that the supplement causes panic attacks.
However, it’s also possible that the difference in outcomes exists for another reason. It could be that dietary changes cause a reduction in panic attacks. After all, if dietary changes cause a reduction in panic attacks, then the same difference in outcomes would exist, except it would exist for a different reason. People who use the supplement would be more prone to panic attacks because they didn’t have the benefit of the dietary changes to reduce their tendencies to have panic attacks.
So, we can see that, in arriving at the conclusion, the author does what this choice says.
(D) It overlooks the possibility that people who use the supplement to lose weight also use dietary changes.The author bases the conclusion on a comparison. The people who use the supplement to lose weight are more prone to panic attacks than people who lose weight through dietary changes only.
Notice that, even if people who use the supplement to lose weight also use dietary changes the argument still works because the point still stands that the people who use the supplement are more prone to panic attacks than people who use dietary changes alone.
(E) It assumes without warrant that those most likely to have panic attacks choose to use the supplement rather than dietary changes to lose weight.Notice that the argument concludes that the supplement causes panic attacks whereas this choice suggests basically the opposite, that people who have already experienced panic attacks choose to use the supplement for some reason.
So, this choice says, basically, that the argument assumes the opposite of what it concludes. Since an argument would not rely on an assumption that conflicts with the conclusion, this choice can’t be correct.
Answer: C