LSAT 14 - Section 4 - Question 18

This is a Flaw/Descriptive Weakening question and we know this because of the question stem: “The argument is most vulnerable to criticism on the grounds that…”

With a flaw question, we’re trying to identify reason(s) the conclusion wouldn’t follow the premises. In other words, we’re trying to extrapolate and explain why the stimulus is flawed, and why the premises don’t support the conclusion. Remember, there could be multiple flaws.

The first sentence goes into percentages. Whenever this happens, it’s always a good idea to pay close attention to what subset or group of individuals/items is being discussed. Here, we know the group is voice recording taken from small planes involved in relatively minor accidents. Great! What about this group? Over 75% of the recordings showed that the pilot whistled 15 minutes right before the accident. The rest of this percentage pie? Under 25% of the recordings when planes were involved in accidents did not record pilots whistling 15 minutes before the accident.

Two things should be going through our minds here: first, this sounds like a statement of facts, and is probably going to be a premise; second, this sounds like correlative language. If that’s the case, what can we draw from this statement? Only that these two instances are correlative! Remember that correlation does not imply causation.

The second sentence is very straightforward, probably a premise or context. At this point, it’s okay not to really understand what function it has in the argument; let’s put it aside and return to it.

Now we’re coming to our last sentence, and it starts with “therefore.” If I haven’t seen my conclusion and this starts with a conclusion indicator, I’m praying this is it. And it is! It’s a conditional conclusion, which means that we’re only concerned with instances where the pilot starts to whistle because that is when our sufficient condition is triggered. Okay, now on to the substance of the conclusion. Why should passengers take safety precautions when the pilot starts to whistle? Presumably, there would be a risk. What’s the risk here? According to this argument, and specifically the second sentence, the risks are the minor accidents that small airplanes are involved in.

The argument is making a jump from whistling to the accident but doesn’t explicitly relay what that relationship is. The part where I say “presumably, there would be a risk” is what the argument is assuming as causation. The argument is assuming that since accidents occur in over 75% of the voice-recorder tapes taken from small airplanes involved in relatively minor accidents where the pilot was recorded whistling 15 minutes prior, then it must be that whistling causes those accidents*.*

We know from the core curriculum that this line of reasoning is ridiculous. You cannot imply causation from correlation! There are a thousand different things that could have caused the accident independent of the pilot whistling. And there are many things we can point to that the argument overlooks. For example, what if most pilots whistle during flying—regardless of the size of the plane and the majority of them—and never get into accidents? What if pilots whistle all the time, but different things caused those accidents? The questions are endless. Now that we’ve identified a flaw, let’s get into the answer choices with our two steps: is this answer choice descriptively accurate? Is this the flaw?

Answer Choice (A) Accepting the reliability of the statistics given by the official is descriptively accurate, but this isn’t a flaw. Firstly, we have to accept the premises of this argument, which would mean that we have to accept the statistics. Second, the reliability of the statistic isn’t what makes our conclusion unsupported. This is out.

Answer Choice (B) Descriptively accurate, but not the flaw. This is trying to confuse you by bringing up statistics. This says in 25% of these accidents (where passengers did not hear the pilot whistle), the recommendation (take precautions once they hear whistling) wouldn’t help because they heard no whistling before the accident. So, what? The argument isn’t concerned about the safety of all passengers; it’s specifically talking about passengers who hear the pilot whistle.

Answer Choice (C) This is descriptively accurate, but again, it is not a flaw. Defining what small accidents are is not pertinent to the inadequacy of the support the premise gives the conclusion.

Correct Answer Choice (D) This is saying that the argument is ignoring the percentage of all small airplanes, including the planes that do not get involved in accidents, in which the pilots whistle. What this answer is trying to say is that the argument is only looking at planes that do get involved in small accidents. What about planes that don’t get involved in those accidents – it could be that the argument is overlooking the much more likely scenario that whistling is something pilots do very often during flights, and the correlation between accidents and whistling is a total coincidence.

Answer Choice (E) This is descriptively accurate, but it’s not the flaw. This answer choice forces the argument to consider the proportion of planes that get into accidents; for example, out of 100 small planes, 25 will get into accidents. So, what? This isn’t relevant to the conclusion, nor is it what makes the conclusion unsupported.