Logical reasoning PrepTest 137 · Section 3 · Question 21

Incorrect. First, this answer is what this group "often" does—it's not a tendency, just something that sometimes drives their decisions. That's not really strong enough to impact the argument. Ignoring that, minivans "show no greater ability to protect their occupants" in crash tests, so this answer doesn't even suggest that low-risk drivers often buy minivans, thus cutting against the argument.

Incorrect. If minivans end up in just as many accidents as other vehicles, then that calls into question if they're being driven by low-risk drivers, as low-risk drivers should be less likely to get into accidents.

Incorrect. If minivans have more passengers per vehicle, yet they have fewer injuries per vehicle, then that suggests either that they're getting into fewer accidents or that they're really safe when in an accident. The crash tests suggest it's not the latter, making it more likely to be the former—they get in fewer accidents. However, there's no way to know if that's because they're safer to drive, because they're driven by low-risk drivers, or some other reason, so this answer doesn't have an impact on the argument.

Incorrect. If anything, this answer undermines the conclusion. The study showed that minivans were no safer than other vehicles "of similar size." If, as this answer states, these larger vehicles are safer than smaller vehicles, then that study is compatible with the vehicle itself being responsible for the safety record, not the driver.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Based on injuries per vehicle, minivans are the safest cars on the road. But studies show they don't protect occupants better than other cars. So this safety must come from low-risk drivers, not the car's safety features.

Answer Anticipation:
The stimulus here brings up a phenomenon—minivans have fewer injuries per licensed vehicle—before concluding something about why that's the case. Interestingly, it mentions both something that is a viable explanation for that phenomenon (low-risk drivers) and something that isn't a viable explanation (inherent safety).

This is particularly interesting because of the effect it has on the logic—not much! If the conclusion just stated that the reason minivans have better safety records than other vehicles is that they're driven by low-risk drivers, and implication of that is that it's probably not because of safety features of the car—in fact, an implication would be that it's probably not any other explanation.

Does that mean we should discount that portion of the conclusion? Absolutely not—the LSAT included it in the argument, and the premise is about those inherent features, so it's the most likely alternative explanation for a correct answer to deal with.

Whenever a Strengthen question proposes a given explanation for a phenomenon (especially a causal one), the correct answer will generally either provide additional support for the concluded explanation, or provide evidence against an alternative explanation. And since the conclusion features an alternative, we can anticipate answers that undermine the safety features of a minivan as explaining the safety record.

Answer Explanation:
The conclusion of the argument has two parts—it rules out one explanation for the safety record (minivans are inherently safer) and proposes an alternative (they're driven by low-risk drivers). This answer choice provides evidence that minivans aren't inherently safer (they have poor braking and emergency handling), thus strengthening the conclusion that the car itself isn't responsible for the safety record.

Key Takeaway:
When an argument concludes one explanation for a phenomenon, it's implying that all other explanations are wrong. As such, you can strengthen that argument either by providing more evidence for the explanation from the conclusion, or by providing evidence against an alternative explanation. And when the stimulus itself brings up an alternative, chances are good that's the one that's going to feature in the right answer.