#14 - In jurisdictions where use of headlights is optional

[mford]

I have a question about:

February 1997, Logical Reasoning Section 1, #14 (use of headlights)

The answer to the question is (C)--which has left me dumbfounded. Why (C) and not (E)?

Thanks in Advance!

[Dave Killoran]

Hey Mford,

You ask about an interesting question. LSAC actually released answers to that February 1997 LSAT, so let me paraphrase from their explanation (which can be found in "The LSAT Explained...The Official LSAT PrepTest With Explanations, Volume One," now out of print).

First, LSAC characterizes this question as "difficult," or, on their scale of difficulty, 4 out of 5. So, you are looking at a tough question (and the answer you chose, E, was the most popular wrong answer).

Second, let's look at the paradox. The stimulus states that in optional headlight usage jurisdictions, drivers who use headlights all the time are less likely to be involved in an accident than drivers who use headlights only when the visibility is poor. But, when headlight usage is mandatory there is no reduction in the overall number of collisions.

That's a pretty tough paradox, because when most people look at the stimulus, they don't see a viable explanation for what is occurring. So, let's look at the two answer choices you asked about.

Answer choice (C): As you noted, this is the correct answer. From LSAC's explanation of the answer choice, this answer plays to the type of drivers in each group. In the headlight optional areas, they see it as a careful set of drivers who use those headlights at all times--thus, they are less likely to be involved in an accident. But, when everyone is forced to use headlights, that group expands to include the less careful drivers, and their driving is not made better by using headlights all the time. Thus, according to LSAC, this answer explains both sides of the paradox.

Answer choice (E): LSAC points out that this answer can explain the second part of the paradox, but that it "does not explain why, in jurisdictions where the use of headlights is optional, drivers who use headlights at all times are less likely to be involved in collisions." Thus, they see this failing to address the first sentence of the stimulus.

Please let me know if that helps. Thanks!

[mford]

Ok, I re-read the explanation you gave and the one on lsac website 10 times and I think I understand now. The key portion seems to be the idea that there are two types of drivers on one side and two attributes of those drivers on the other. On the driver side, there are the ones that use headlights and those that don't. On the attributes side there are the careful and the imprudent. I think what's going on here is that LSAC finds that there is a natural ambiguity of cause and effect---one that only the correct answer addresses, but could easily be taken to be insignificant or a side issue (only careful people use headlights when their use is not required, so whether or not their use is mandated would not impact this driver-type and implicitly may not effect their counterparts).
The confusion comes with the smoke-screen created by the headlights issue--As you say, nothing logical seems to resolve the paradox, so we're left with strange hypotheticals which could fit the bill. I was particularly stuck on the idea that headlights have 'duel-use' properties that allow not only for drivers to see better, but to be seen better by others (bringing in the idea of the environment having a greater impact as in E). And so the premise just doesn't make sense at all, by virtue of the facts presented that do not accord with common sense but I suppose it doesn't have to. A very strange psychological trick!
______
This is one of those questions where I originally marked off all the answers as bad answers, and had to go back to the question---I suppose going to the purpose of resolve the paradox, remembering what my mission is in the context of this question type is, even amidst the panic-ey time crunch would have been key. Thanks for the help!

[Dave Killoran]

That's a good analysis, and a nice breakdown of the attributes in play. You know there's a difference in the two situations, and then they use the careful/imprudent difference as the cause.

For what it's worth, I've always thought of this question as one of the harder Resolve questions out there.

Thanks!

[kegan62]

I still don't get it. Their explanation is that having their headlights on doesn't turn unsafe drivers into safe drivers. But it doesn't need to. Unsafe drivers don't have to turn into safe drivers in order to have fewer accidents. They just need to be able to see other cars in unsafe conditions, so that they (like cautious drivers) will (for example) actually see the car coming towards them in the opposite direction in dim/rainy/any poor visibility condition.

Safe drivers will pause and look quite carefully to make sure there's no "invisible" silvery car coming towards them without lights on in poor visibility before turning left across oncoming traffic. Unsafe drivers just make the turn without thinking about how poor visibility is, and don't pause or stop and carefully check the opposite lane. But if all drivers have their headlights on, the unsafe drivers will easily see that there's a car coming, and won't make the left turn until that car has passed.

The statistics the question offers may be accurate, but answer C doesn't address why drivers' actually seeing a car coming towards them (rather than not seeing it, in the rain or twilight or what have you) doesn't lead to fewer accidents.

Nobody ever said that unsafe drivers' having their lights on makes them safer drivers. Yet they suggest that we think this.

So: I still don't get it.

[Rachael Wilkenfeld]

Hi Kegan.

There are two groups of drivers, and two different conditions. The first condition is where headlights are required all the time. There, both cautious and non-cautious drivers use headlights in all conditions. The second condition is where headlights are optional in good visibility. There, all drivers use headlights in low visibility. But in good visibility, only some drivers use their headlights.

You seem to be focusing on unsafe drivers in bad visibility. But in both the always required and sometimes optional headlight scenarios, both all drivers would have their headlights on in that scenario. The divergence comes when the weather is good. When visibility is high, only some drivers in headlights optional jurisdictions will use their headlights, but all drivers in headlights required jurisdictions will have their headlights on. That's the behavior divergence.

The other divergence is in results. In headlight optional jurisdictions, those who use them anyway are less likely to be in an accident than those who do not. But making the headlights required doesn't reduce the overall accident rate.

We could think of two potential causal relationships. It could be that the headlights cause the accident reduction. That would explain the decreased accident likelihood for headlights on drivers in optional jurisdictions. However, that doesn't seem likely given that requiring the headlights for everyone doesn't reduce overall accident rates.

The second possibility is maybe somehow cautiousness or low accident likelihood causes the increased headlight use. That would explain why the headlights on drivers in optional headlight situations have lower accident rates, but the overall rate accident rate doesn't decrease when requiring the headlights for everyone. It's not the headlights causing the cautiousness, it's the cautiousness causing the headlight use. The headlights themselves in this situation aren't doing anything other than marking who is cautious and careful enough to use them when not required. That's why requiring them for everyone doesn't change the overall accident rate.

Hope that helps!

[kegan62]

Of course!! Thank you Rachael!