You Try - Minivans and Sports Cars

Let’s try another LR question to give you another taste of what you’ll see in this section.

Let’s start by reading what the question asks us for.

The reasoning in the driver's argument is most vulnerable to criticism on the grounds that this argument

Apparently the driver’s argument will be vulnerable to criticism. This raises two concepts that you’ll learn a lot more about later – what is an argument, and what does it mean for an argument to be vulnerable to criticism?

You can think of an argument as an attempt to persuade you of something based on reasons. The thing someone’s trying to persuade us to believe is called the conclusion. A reason offered for why we should believe the conclusion is called a premise.

An argument is vulnerable to criticism when the reason(s) offered by the driver don’t do a good job of showing that what he’s trying to persuade us of is actually correct.

Let’s see what the driver says and identify (1) what he’s trying to convince us of – the conclusion, and (2) the reason(s) offered in support – the premise(s).

My friends say I will one day have an accident because I drive my sports car recklessly.

This isn’t the driver’s own argument yet. The driver is simply telling us what his friends say. From this statement, we learn that the driver apparently drives a sports car, and he does so in a dangerous (reckless) way.

But I have done some research, and apparently minivans and larger sedans have very low accident rates compared to sports cars.

Minivans and larger sedans have much lower accident rates than sports cars.

So trading my sports car in for a minivan would lower my risk of having an accident.

The driver makes a prediction – if he gives up his sports car and starts using a minivan instead, that would lower his chance of getting into an accident.

The word “so” at the beginning of the last statement tells us that the driver believes the last statement is proven by the statement before it. The driver’s trying to persuade us that switching from a sports car to a minivan would lower his accident risk. This is the conclusion. And why should we believe this? Because, the driver says, minivans have a lower accident rate than sports cars. This is the premise.

Anticipate

To identify how this argument is vulnerable to criticism, let’s think about why the premise does not do a good job of proving the conclusion.

From the driver’s research, we know that minivans have a lower accident rate than sports cars. Does that prove we can take someone who drives a sports car, put them into a minivan, and they’d reduce their risk of getting into an accident? If you’re new to the LSAT and logical reasoning, you might think it does. But let’s consider some analogous arguments first, and then see what your intuition tells you.

People who eat a lot of seafood are more likely to exercise than people who eat a lot of red meat. So, I can increase the chance I’ll exercise by starting to eat a lot of seafood.

Hmm, that sounds… fishy. The people who eat a lot of seafood are more likely to exercise…but that isn’t because seafood is somehow increasing how much they run or lift weights. Couldn’t it be that there are people who care about healthy lifestyle habits, and these people are more likely than the average person both to eat lots of seafood and to exercise?

So, if you start to chow down on nemo, we can’t expect that to make you exercise more, because the act of eating seafood doesn’t necessarily change you into the kind of person who cares about a healthy lifestyle.

Here, consider another analogous argument.

People who memorize the phone number and address of the local U.S. embassy when traveling to another country are less likely to lose their passports. So, I can reduce the chances of losing my passport when traveling if I memorize the phone numbers and addresses of the U.S. embassies in the countries I travel to.

Wait…that doesn’t make sense. How can memorizing a phone number and address change the chance you lose a passport? What’s really going on is that the kind of person who memorizes the contact info of U.S. embassies when traveling is probably the kind of person who’s more careful about where they keep their passport and more vigilant about pickpockets. If you aren’t this kind of careful person, simply beginning to memorize contact info of U.S. embassies won’t necessarily change your habits when it comes to protecting your passport and other personal belongings.

Now, let’s come back to the driver’s argument.

Minivans have a lower accident rate than sports cars. So, I can reduce my accident rate by switching from a sports car to a minivan.

Do you see the problem now? The reason minivans have a lower accident rate than sports cars might be that the kind of person who drives a minivan tends to drive more carefully than the kind of person who drives a sports car. Think about who typically chooses to drive a minivan – parents with young children? The parents who drive minivans would probably drive extra safely no matter the kind of vehicle they’re in, because they’re trying to protect their family. They’ll always use their turn signals, they’ll follow the speed limit, they’ll come to a full stop at red lights before turning right, etc.

On the other hand, people who drive sports cars probably aren’t carrying a bunch of toddlers in the backseat. They probably won’t drive as carefully as the parent in a minivan. They might have purchased a sports car in order to drive fast.

So, if you as a hotshot sports car driver switch into a minivan, we can’t expect this to change your accident rate, because it won’t necessarily make you a more careful driver.

At this point, I want to make sure you’re aware there’s a very standard label for the bad reasoning used by the driver – this is something we’ll cover later in the curriculum. If you were about to take the LSAT, you’d want to be damn sure you know that label and can recognize it in the driver’s argument. In fact, at this point ideally you’d know what answer you’re looking for and go hunting for it. But, since you’re just at the beginning of your studies, and won’t know all the LSAT lingo, let’s go through the answers carefully and stumble upon the right one.

Answer Choices

I’ll address the answers in order from the least picked to the most picked. The question is, does this answer describe why the driver’s argument is most vulnerable to criticism?

Answer Choice (B) relies on a sample that is too narrow

If you conduct a poll to predict the outcome of the presidential election, but only asked your neighbors, you probably won’t get a very accurate prediction. The sample of voters in your poll would be too narrow – it wouldn’t capture the broader population that will vote, which includes lots of people who aren’t your neighbors.

Does the driver’s argument have this kind of problem? No – there isn’t even a sample in the first place, much less a sample that’s too narrow. The driver does bring up statistics about the accident rates of minivans and sports cars, but there’s no indication that this statistic is based on a narrow sample of minivans or sports cars. The author didn’t say, “The Honda Odyssey has a lower risk of accident than a Lamborghini. So, minivans have a lower risk of accident than sports cars.”

Answer Choice (E) relies on a source that is probably not well-informed

If you want to know how to fix a malfunctioning nuclear reactor, you probably wouldn’t ask a random 6-year-old for advice. Why not? Because she’s just a kid. What could she possibly know about nuclear reactors and how to fix them? If you do ask her what to do and follow that advice, you’d be relying on a source that’s probably not well-informed.

Does the driver’s argument rely on a source – something the driver cites as an authority for support? Well, the driver does bring up statistics about minivans and sports cars. But we don’t know anything about where this statistic came from. The driver didn’t say, “According to a random 6-year-old, minivans have a lower risk of accident than sports cars.” So, we have no basis to speculate that the source of the statistic is not well-informed, because we don’t even know anything about the source in the first place.

Answer Choice (C) misinterprets evidence that a result is likely as evidence that the result is certain

The local news forecasts that rain is likely tonight. Does that imply that rain tonight is certain? Obviously not. If something is “likely” to happen, there’s a greater than 50% chance it will occur. But “certain” means 100%. And greater than 50% clearly doesn’t have to mean 100%.

Does the driver’s argument start with evidence that a result is likely, but interpret that as evidence a result is certain? Not at all. There are multiple reasons to eliminate this answer, but I’ll focus on the one that’s most clear. The driver doesn’t interpret anything as showing that a result is certain. The result we’re talking about is the result of avoiding an accident. Notice that the driver’s conclusion is just that switching to a minivan would “lower my risk of having an accident.” That doesn’t mean the driver thinks avoiding an accident is certain. A lower risk could mean going from 30% chance of accident to 25%, for example.

(If you interpret the “result” in (C) as the entire concept of “having a lower risk of accident” as opposed to the avoidance of accidents, then (C) might be more tempting. But in this case (C) is still wrong because the evidence doesn’t establish that “having a lower risk of accident” is likely to occur. In fact, if you think the evidence shows this, you’re adopting the same bad reasoning the driver’s argument uses. Remember, minivans’ lower rate of accidents doesn’t need to have anything to do with minivans; it could be due to the kind of person who chooses to drive a minivan. So the statistic cited by the author doesn’t show that switching to a minivan is likely to change anything about one’s chance of getting into an accident.)

Answer Choice (D) mistakes a condition sufficient for bringing about a result for a condition necessary for doing so

Remember the terms “sufficient condition” and “necessary condition” from the Coffee Shoppe problem? A sufficient condition is a condition that, if true, guarantees something else is true. A necessary condition is a condition that must be true in order for the sufficient condition to be true. So, in the Coffee Shoppe problem, an increase in bean price was sufficient for a decrease in the Coffee Shoppe’s profitability. But that didn’t imply that an increase in bean price was necessary for a decrease in profitability. The Coffee Shoppe’s profitability could still decrease for some other reason unrelated to an increase in bean price.

Does the driver’s argument interpret a sufficient condition as a necessary condition? No – there aren’t any sufficient conditions described in the argument. The driver’s premise is a statistic about minivans and sports cars – minivans have a lower risk of accident than sports cars. Does that mean driving a minivan guarantees avoiding an accident? Or driving a sports car guarantees getting into an accident? No. So, there’s nothing that we can accurately describe as a “sufficient condition.”

(D) describes an argument that looks like this:

If one drives a sports car, one will get into an accident. My friend got into an accident. So, my friend drives a sports car.

This argument isn’t convincing, because other kinds of cars can also result in accidents. But this isn’t the problem in the driver’s argument.

Answer Choice (A) infers a cause from a mere correlation

Correct! “Inferring cause from correlation” is the standard label I mentioned earlier for the bad reasoning in the driver’s argument. If you haven’t heard of this concept before, (A) is hard to pick. But even if you do know this concept, the driver’s argument disguises this problem well. Before I get into how (A) is correct, let’s get some basic definitions out of the way first.

A correlation is a relationship between two variables such that knowing about one of the variables tells you about the other. For example, in children, shoe size is correlated with intelligence, because, on average, a child with a larger shoe size will be more intelligent than a child with a smaller shoe size. And, a child who is less intelligent will, on average, have a smaller shoe size than a child that is more intelligent. (We’re just talking about averages – we’re not making any definitive claims about specific children.)

One thing causes another thing if it plays a role in producing that thing. Although shoe size and intelligence are correlated, neither causes the other. Both are caused by a child’s age. As children grow up, their shoe size increases and they become more intelligent.

So, how does the driver’s argument infer cause from correlation?

The statistic about minivans and sports cars presents a correlation. There’s a correlation between the kind of car one drives and one’s chance of getting into an accident. If you know someone drives a minivan, on average, that person has a lower chance of getting into an accident than someone who drives a sports car.

The driver believes this statistic proves a causal relationship between the kind of car one drives and accident rate. In the driver’s mind, the reason minivans have a lower accident rate than sports cars is that there’s something about a minivan that produces fewer accidents – the minivan is inherently safer. That’s why the author believes that switching from a sports car to a minivan will lead to a lower chance of accident.

But this causal interpretation of the correlation is unwarranted. As we went over earlier, the true explanation for the correlation could be the kind of person who chooses a minivan vs. a sports car. The minivan itself doesn’t have to produce a lower accident rate; rather, a more careful driver chooses to drive a minivan over a sports car, and this driver’s habits produce a lower accident rate.

Takeaway

This LR question is chock full of takeaways. First, it’s a great example of a common kind of bad reasoning called inferring cause from correlation. You’ll see this at least once on every single LR section, and usually more than once.

In addition, eliminating wrong answers in this question requires a strong understanding of other kinds of bad reasoning – confusing sufficient and necessary conditions, relying on a narrow sample, inappropriate appeal to authority, inferring certainty from likelihood.

And it also brings up more basic issues that you might not be familiar with yet – premises, conclusions, evaluating what makes arguments vulnerable to criticism.

Of course, the Core Curriculum will cover all of these in detail. But, I want to emphasize something else that you’ll get from the curriculum, the value of which might not be apparent yet.

Do you notice that, in explaining this question, and the previous one concerning the Coffee Shoppe, I relied a lot on analogies, or I appealed to your real-world intuitions about things like what might cause minivan drivers to get into fewer accidents, or what might cause a coffee shop to have decreased profitability besides an increase in bean price?

Analysis based on real-world intuitions can be very useful, and if you’re particularly clever, may have helped you get both of these questions correct. But each LR section presents you with about 25 questions, one after the other, under intense timing pressure. If you need to rely on analogies to understand why correlation doesn’t prove causation, or you need to think about real-world reasons a particular sufficient condition doesn’t have to be necessary, you’ll struggle mightily, because you won’t have enough time to think through these issues for every question.

The only reliable path to a high score in LR is recognizing the underlying logical structures.

You want to see “minivans have a lower accident rate than sports cars” and immediately think “X is correlated with Y” and immediately be on the lookout for the argument to improperly infer “X causes Y.”

You want to see “If the bean price increases, then the profitability decreases” and immediately think “X is sufficient for Y” and immediately register that this doesn’t mean “Y is sufficient for X.”

This kind of structural understanding is what the Core Curriculum is designed to build.