Ok, I am joking about this being the hardest LR question of all time. Of course, there have been harder questions, but for some reason, this one took me days and days to get....
First of all, this is a very unique principle question. Usually, the correct answer to a principle question is a conditional or just look likes a principle-you know, has a "should" or the equivalent of a should in there somewhere....but this problem looks more like a "find the necessary assumption question."
I get why A is the correct answer. It fills in the gap between the premise and conclusion. The premise is that certain factors can increase or undermine a witness' confidence without hurting the accuracy or reliability of identification. Then there is a big jump to a conclusion (which comes out of nowhere!) that states that thus, based on the abovementioned premise, police officers are advised to stop suspect lineups in which witnesses can hear one another identifying suspects...So the big assumption here is that the confidence of witnesses in suspect lineups is affected by hearing other witnesses identifying suspects, and that's how A connects the premise to the conclusion.
But the thing which took me so long to get was, why would this matter?!?! Why would police officers disallow suspect lineups in which witnesses can hear one another identifying suspects because it might affect their confidence levels, if their level of confidence has no effect on the reliability of their accuracy?
So I talked to my dad about it, who is in the military and thinks more like a cop, and he said that if a witness' confidence is lowered, they might not be as forthcoming about what they think, and they might be less willing to cooperate.
What do you guys think?
Comments
First point i want to make is that its not worth it to get so frustrated by how unrelated the conclusion is to the premises. Every single LSAT argument has a conclusion with a relatively weak connection between premises and conclusion, its just that in other 'easier' questions, the assumption you need to make in order to link them is something to which you can more easily relate. An easy LSAT question might say that (this is a real example) the government ought to do everything in its power to help low-income parents, and then conclude that the government ought to provide free day care for low-income parents. This isn't a valid argument because just because free day care for low-income parents sounds like something that would help low-income parents, that doesn't mean it necessarily must; it just sounds like it does because it seems obvious, but as aspiring lawyers, we make no assumptions. We require justification for everything. I don't really care why low income parents would benefit from day care; i just need to know that they would in order to make my argument.
Obviously, its critical to think about and understand the link between the premise and conclusion in an argument, but the 'out of the blue' conclusion that we ought to disallow suspect lineups in which witnesses can hear one another isn't any more out of the blue than the conclusion that we ought to provide free day care for low income parents, from the point of view of sound logical principles.
Answers to principle questions sometimes are phrased as conditional statements that often function as sufficient assumptions (PT 54 S2 Q18 is a good example), but often they are necessary assumptions, something that i see a lot on the reading comprehension sections. So its important to keep an open mind when doing principle questions.
In answering your question "Why would police officers disallow suspect lineups in which witnesses can hear one another identifying suspects because it might affect their confidence levels, if their level of confidence has no effect on the reliability of their accuracy" it is important to realize that we'll never know for sure without speculating, precisely because the argument is so poor. I can provide you with an answer that could or could not be wrong. I suspect that it would be harmful to the legal process if witnesses were especially confident in inaccurate reports, or especially not confident in high accuracy reports. I'd prefer a confidence level as unadulterated as possible given that it has no relationship to accuracy, since if i have suspect lineups somehow making them more confident, than i run the risk that a potentially inaccurate story from a witness will be believed more easily. If i were to ask you why free day care benefitted low income parents, you might respond that they would otherwise need to pay for expensive babysitters that would put a strain on their already low incomes. But who knows why it would really help? Maybe it would help because low income parents hate their children and prefer not to spend time with them. Or because they work especially long hour jobs on weekdays and are never home during the day. I can imagine a link between the premise and conclusion, but any link would necessarily be speculative. (The argument i'm using here is pretty much the same as PT 47 S1 Q20)
That's just my speculative assessment, however, an assessment i can never know to be true. Answer choice A also does not specify as to whether the suspect lineup discussions increase or decrease confidence levels, so it is even more difficult to pinpoint the direct link between the premise and conclusion with any degree of certainty. But again, that ambiguity and the difficulty it presents to the test taker is precisely the point. The LSAT intentionally writes ridiculous arguments, and this one is no different than the day care argument. I just need to know day care is something beneficial to our low income parents. Similarly, i just need to know that suspect lineups of this variety are related to confidence. Why are they related? That's not something we're required to determine because we'll never know. Even with answer choice A, which definitely makes our argument stronger, we still have a weak argument. Supplying a necessary assumption plugs up a potential hole in our argument, but it doesn't get us anywhere near validity. It just gets us from crappy argument to less crappy argument. And every LSAT argument is crappy; strengthening, or providing a necessary assumption, simply makes it less crappy.