#12 - A survey of a group of people between the ages of 75

[Administrator]

Complete Question Explanation

Method of Reasoning-CE. The correct answer choice is (D)

This argument involves causal reasoning. A survey indicates that among people aged 75 to 80, people who play bridge tend to have better short term memories than those who do not play bridge. The stimulus points out that the original conclusion was that bridge assists memory, but challenges that conclusion by considering the possibility that people with better memories are more likely to play bridge.

You should realize that the argument utilizes one of the stock methods of challenging a causal argument by suggesting that the cause and effect could be reversed. That is, the study concluded that bridge playing causes memory abilities, but the stimulus mentions that memory abilities could cause bridge playing.

Answer choice (A) An argument that involves representation will involve a comparison between a sample and a population. If the argument only considers those surveyed, there is no representation error. Simply mentioning a survey in the stimulus does not mean there is any kind of representation error, and this choice is wrong. The LSAT test writers repetitively test whether you pick up on that detail.

Answer choice (B) The stimulus never concedes the study's conclusion, and never discusses therapy.

Answer choice (C) The stimulus considered the possibility that the original conclusion might be flawed, but did not assert that the conclusion was definitely wrong, so this choice is incorrect. Furthermore, it is unclear what motives the original conclusion considered.

Answer choice (D): This is the correct answer choice. The stimulus proposes a reversal of cause and effect, and that is an alternative hypothesis. You should remember that it is somewhat frequent for LSAT test writers to refer to a change in causal explanation as simply a change in hypothesis or change in explanation.

Answer choice (E): This is an attractive answer choice, because the implication in the stimulus is that the study engaged in flawed reasoning. However, there is a difference between describing a flaw and actually making an alternative proposition that addresses the flaw. A description of the flaw, in this case, would involve a statement such as: "However, since the correlation of factors does not prove which of those factors, if any, is the causal element, this study may be flawed." Since the stimulus instead pointed out an actual causal alternative, the stimulus did not describe the flaw; it simply addressed the flaw.

[kcho10]

Hi,

Could someone please give a specific example of an argument that questions the representativeness of the sample surveyed? What change in wording or additional phrase/sentence would make this qualify as this type of argument?

[David Boyle]

Hi,

Could someone please give a specific example of an argument that questions the representativeness of the sample surveyed? What change in wording or additional phrase/sentence would make this qualify as this type of argument?

Hello kcho10,

If, say, there were an assertion, "All the ones who played bridge were then also given, free of charge, a 'how to improve your memory' course", then the sample comprising those particular bridge players might not be truly representative of average 75-80 year old bridge players, since most of the latter do not receive a free memory-improvment course just because they play bridge.

Hope this helps,
David

[egarcia193]

I don't understand why D is correct I understood the causal reasoning in the argument and tried to find an answer choice that matched it but I eliminated D because it talked about the data and not the relationship between bridge and memory where answer C actually discussed the relationship although by describing motives it was the closest one I could see that describes the causal relationship. Why is D right and C wrong I don't understand

[AthenaDalton]

Hi egarcia,

We know from the study that people with good short-term memory are more likely to be bridge players than people with poor memory.

The first explanation for this is that playing bridge actually causes the improvement in memory (e.g. playing the game, which relies on memory, improves your memory).

The second explanation for this is that people who already have good memories enjoy playing bridge because it's a game that plays to their strengths (e.g. playing the game, which relies on having a good memory, is most fun for people with good memories).

Answer choice (D) accurately explains what the second explanation is -- an alternative explanation that explains the data about bridge players having good memories. The stimulus introduces the second explanation by saying "it may well be that bridge is simply more enjoyable . . ." The second explanation is presented as an alternative solution.

Answer choice (C) is incorrect because the argument in the stimulus doesn't rely on the motives of the bridge players. We don't know anything about their motives -- are they playing bridge as part of a conscious effort to improve their memories, or just because they think it's a fun game? We don't know. Since the survey didn't inquire into the players' motives, we can't make assumptions about those motives.

Hope this makes sense! Good luck studying.

Athena Dalton

[egarcia193]

Thanks, that certainly does help me in seeing for why C was wrong and I think I eliminated D before because although it gave an alternative hypothesis about a causal event the fact that it talked the data just seemed to have thrown me off from thinking it was correct.

[gweatherall]

I actually chose B because I thought "conceding the relationship" simply meant conceding that there WAS a relationship/correlation, not conceding which direction the casualty ran. In other words- even if it is true that people with better memory are more likely to play bridge, and not that bridge improves memory, isn't there still A relationship?

How do I know from the answer choice that they are referring to the specific causal order? Can I always assume that to be the case in similar questions?

I also thought that "therapy" referred to playing bridge to improve/maintain memory. Does that make sense at all?

Thanks!

[AthenaDalton]

Hi gweatherall,

There's a couple of ways we can eliminate answer choice (B). Keep in mind that we're looking for an answer choice which describes how the author's counterattack progresses (the counterattack is the last sentence of the stimulus).

First, in the context of this argument, I think that "conceding the suggested relationship" amounts to admitting that the study's main conclusion was correct. The author doesn't concede that the study's conclusion was correct; he really attacks the entire underlying premise of the study.

We should also be skeptical of answer choice (B) because it mentions therapy. I think your assumption about therapy is a reasonable one since it's strongly implied in the stimulus ("playing bridge can help older people retain and develop memory"). However, the author's counter to the conclusion that playing bridge improves memory doesn't progress by discussing the utility of therapy, his counterargument attacks the very causal link between bridge and memory improvement.

I hope this makes sense. Good luck studying!