LSAT 158 - Section 2 - Question 23

This is a Principle question.

We are to extract from this argument by analogy the underlying principle. The right answer states the principle, and the argument in the stimulus is an application of that principle.

The argument contains a premise about SUV drivers and a conclusion about cancer and smoking. It’s an argument by analogy. In order for the reasoning by analogy to run through, both the premise and conclusion have to conform to some underlying principle. Otherwise, what happens with drivers and SUVs would have little bearing on cures for cancer and behaviors like smoking.

The premise says that drivers of SUVs have the correct belief that because they're in an SUV, they're better protected. They have lower risk of serious injury. As a result, their behavior changes. Because they know they’re safer, they start to drive more recklessly. They know the negative consequences are not as bad, so they start to take on more risk.

The conclusion says that the discovery of powerful cures for certain high-incidence forms of cancer would probably trigger an increase in behaviors such as smoking and overexposure to sun that are known to increase the risk of such cancers. If we have a cure for lung cancer, then more people would smoke more. If we have a cure for skin cancer, then more people would overexpose themselves to UV light.

Is this analogous to what was described in the premise? Yes, because there is an underlying principle at work here: mitigating or eliminating the negative consequences of an action invites increased participation in that action. Another way to state that is if the risk of harm is decreased, then people will engage more in that form of risky behavior. This unifying principle is what ties together these two totally different situations. It’s how this argument’s reasoning by analogy runs through.

Answer Choice (A) says when people believe that there are several measures they could take to reduce the risk associated with a certain activity, generally they will only take the measure that they believe will most reduce that risk. That’s not the principle at work here.

For the argument to conform to this principle, we’d have to show several measures to reduce the risk associated with driving and then have the driver pick the most effective one. So maybe one measure is to get into an SUV. A second measure is to put on your seatbelt. A third measure is to have airbags. The fourth measure is don't run red lights. According to (A), the principle here is that you assign some probability to each measure and then pick the measure that will most reduce the risk associated with driving.

Correct Answer Choice (B) says the development of ways to protect people from the consequences of behavior that would normally harm them often makes people less careful to avoid such behaviors.

Yes, that’s the principle. “Behaviors that would normally harm them.” What kind of behavior are we talking about here? If applied to driving, then we’re talking about reckless driving. That's behavior that normally would harm you. “The development of ways to protect you from the consequences of reckless driving” is putting you in an SUV. Because when you're in an SUV, it lowers the risk of serious injury as a result of accidents. And as a result, you are less careful to avoid reckless driving.

It’s the same in the conclusion. The behavior that normally would harm people is, say, smoking. If we develop ways to protect people from the consequences of smoking, i.e., lung cancer, then that's going to make people smoke more.

(B) is correct because it extracts the underlying principle that analogizes these two seemingly different situations.

Answer Choice (C) says that people generally take special care to avoid behaviors that they believe would likely lead to serious harm and generally do not take special care to avoid behaviors that they believe will not harm them at all. That’s not the principle at work here.

What behaviors would likely lead to serious harm that people are avoiding? Reckless driving? But if that's the behavior, there's no indication that people are taking special care to avoid reckless driving. What behaviors won't cause harm? The argument doesn’t say. (C) has a hard time mapping onto the argument.

We could make up an argument for (C) to map onto. In general, when traffic lights turn red, everybody stops. When the lights turn green, everybody goes.

This maps onto (C). People are taking special care to avoid behaviors (running a red light) that they believe will likely lead to serious injury. People are not taking special care to avoid behavior that they believe will not harm them (running a green light). In other words, people run green lights.

Answer Choice (D) says people generally exercise more care when performing activities that they know to have risky consequences than when performing activities of unknown risk. That’s not the principle at work here.

To illustrate the principle in (D), consider two activities. Activity one you know is risky. Activity two has a risk profile that’s unknown to you. It could be just as risky, less risky, or more risky than activity one. (D) is saying that people are more careful when performing activity one. This doesn’t map onto the argument.

Moreover, I'm not sure this is a reasonable attitude. If you don't even know the risk profile associated with an activity, wouldn't it be prudent to be extra careful just in case?

Answer Choice (E) says avoiding serious harm to themselves is given a high priority by people in their behavior but avoiding lesser harm is frequently outweighed by various desires. That’s not the principle at work here.

To illustrate the principle in (E), consider the serious harm of losing your arm. You’re going to be very careful to avoid that kind of harm. Now consider the less serious harm of getting a bruise. People regularly choose to risk getting bruised because they have other desires that are more important to them. For example, if you go hiking, you might get bruised. If you play basketball, you might get bruised. The desire to go hiking or play basketball often outweighs the lesser harm of getting a bruise.

If applied to driving, then avoiding serious harm is given a high priority by people in their behavior. That’s why people don’t run red lights. But avoiding less harm is frequently outweighed by various other desires like wanting to get to a destination faster. That’s why people speed. Speeding is not as serious as running a red light, but it does increase your chances of getting hurt (and hurting others).