This is a strengthening question, as we are asked which answer choice: if true, provides the most support for the argument?
The stimulus begins by informing us that there are two subsets of a particular species of bird; crested and non-crested. The birds usually live in flocks composed of only one of these subsets, and have a preference for birds of the same variety as themselves. So in a crested flock you are likely to find only crested birds, and these birds will likely select crested mates. Interesting! We are further told that even if you move a bird from a flock where all the other birds are crested into a mixed flock, it will select a crested mate regardless of whether it itself is crested or non-crested. It’s important in this sentence that we realize that a flock where all other birds are crested does not mean the bird in question is itself crested. So it seems like non-crested birds from crested flocks will go against the general trend of the birds selecting mates of the same type. The author concludes from this that the preference for mates is learned rather than genetically determined.
If we think about the author’s reasoning, it does make some sense. We would expect birds to mostly select the same kind of mate if preference was learned since flocks are usually composed of one type, and this would also explain why there are exceptions when a bird is raised in a flock mostly of the other type. Since we are choosing one hypothesis (learned) over another (genetic) we should look for answers that support the learned hypothesis over the genetic one. Let’s look at our options:
Answer Choice (A) OK? First of all we are not interested in other bird species, we are interested in why this particular species has a pattern in its preferences for specifically whether a mate is crested or non-crested.
Answer Choice (B) Interesting! But we want support for why a particular behavior (mate selection) is caused by nurture rather than nature.
Answer Choice (C) We want to know why they have a particular preference, not whether they have other preferences.
Answer Choice (D) This actually weakens our learned trait hypothesis, because it shows that a bird can have a mating preference if there was no opportunity to have learned it since the bird was raised in captivity.
Correct Answer Choice (E) This strengthens our learned hypothesis by showing that in the absence of a crested or non-crested homogenous flock, birds lack the mating preference. This is what we would expect if the preference was learned, and not expect if it was genetic.
This is a very standard NA question stem. If the argument depends on an assumption, the assumption is necessary.
So the plastic rings on a six-pack ensnare and suffocate animals. Yeah, I’ve definitely heard this and always try to cut these up before discarding. I don’t know if it actually helps, but can’t hurt. Anyway, what about it? Oh okay, new rings that will disintegrate after three days of sunlight. A few things about this sentence. First, is this going to work? I mean, it seems like these might get this much light just in shipping and handling before their job is done. This does not matter though. Despite any potential downside, this statement tells us that ALL beverage companies will soon be using these rings. That seems like a pretty big shift. Good. And once we complete the switch to the new rings, the threat plastic rings pose to wildlife will be eliminated. So this is the conclusion.
I can see a few possible problems here, but we don’t want to go hunting for anything specific. For NA questions, it is best to go into the answer choices with an open mind. Let them speak to you and consider the issues they suggest.
Answer Choice (A) Does this have to be true for the argument to work? No. What if some of them will disintegrate in only two days? Well that might be a problem as far as these rings efficacy as packaging, but our conclusion is only about eliminating threat to wildlife. If three days is good, two seems like it would be even better. So when we negate this, it seems to only make things better for our wildlife friends.
Answer Choice (B) We don’t care about this at all. What matters is that these companies are making the switch. End of story. This can bankrupt them for all we care.
Correct Answer Choice (C) So if this isn’t true, has the threat been eliminated? I would have to say it has not. Three days seems like fast disintegration time, but now that this answer directs my attention to it, the conclusion is quite strong. Our argument is claiming to eliminate the threat. Elimination is as absolute as it gets. But these things have up to three days to be out there before they fall apart. And that’s enough time to harm some wildlife. So now it seems the threat is not eliminated without this answer choice. The argument does, indeed, require this to be true. So this is our answer.
Answer Choice (D) Interesting suggestion, but this is not necessary. If we negate this, we’re only expanding the harms being caused by the old rings. But the conclusion is limited to eliminating the threat of suffocation—not all possible threats—so even if there are other threats, they are not relevant to our argument.
Answer Choice (E) Well I certainly hope not. Regardless, does this have to be true? No. We care about the threat of suffocation which remains a threat even if some animals are able to escape the rings. A threat need not be universally fatal to qualify as a threat. A 99% mortality rate would still be quite threatening.
Answers D and E may be tempting because they address the old rings. There is no reason to believe that the old rings will immediately disappear from the environment. They may continue posing a threat even after their use is discontinued in new packaging. So there is an additional necessary condition for this argument which concerns eliminating the risk posed by the old rings, but this answer does not express that assumption correctly. This alternative necessary assumption is a likely pre-phrase, and the possible existence of multiple necessary assumptions is why this strategy is not recommended for the question type. If you D or E based on a pre-phrase, ask yourself: Did you really scrutinize answer choice C to consider what it was suggesting? Or did you dismiss it because it didn’t match your expectation?
Here we have a strengthening questions, since the question stem demands: Which one of the following, if true, most strongly supports the conclusion drawn from the survey results?
The stimulus starts with the claim that financial success does not guarantee happiness. We should pause here and think about what a guarantee means. If something guarantees something else, then it is sufficient for something else. So what this first sentence really means is that it is not true that if you are financially successful then you are happy; financial success is not sufficient to produce happiness. The next sentence reveals the author’s position, as they assert that this claim has been verified by statistics. Interesting! Since this is a strengthening question, we want to anchor ourselves in this conclusion and get a good sense of what is supporting it. The final sentence introduces the support and tells us about a recent survey, where only one-third of respondents who claimed financial success also reported that they were happy.
If financial success did guarantee happiness, we would expect 100% of people with financial success to report that they are happy. The fact that only 33% did so is good evidence for our author’s conclusion. Unfortunately, there is just one problem. If we read the last sentence carefully, our sample for this statistic is composed of people who claimed to have financial success. Self-reporting should never inspire confidence. While there are many ways to strengthen this argument, we should be on the lookout for an answer that strengthens the connect between the respondents and being truly financially successful. Let’s see what the answers have in store for us:
Correct Answer Choice (A) This does exactly what we noticed the support needed. It strengthens the connection between our sample and actual financial success. If this is true, it guarantees there are at least some people who are financially successful and not happy, and therefore it is impossible that financial success is sufficient for happiness.
Answer Choice (B) We don’t care what people used to think or do think, nor whether financial success is necessary to happiness. Our conclusion is that, regardless of opinion, financial success is not sufficient for happiness.
Answer Choice (C) Financial security being sufficient for happiness wouldn’t mean that it is necessary to have financial security to be happy, so the existence of happy people without financial security isn’t strong support for our position. Even worse, this study still has the problem of self reporting.
Answer Choice (D) We are only told about what proportion of respondents who did report financial success were happy, we don’t know anything about the respondents who didn’t. Even if they were financially successful, maybe the all reported they were happy, in which case our argument would actually be weaker. Not enough information here.
Answer Choice (E) This would weaken our support by making a larger portion of those who reported financial success actually be happy.
This is a must be true question, since the stem asks: If the claims above are true, which one of the following must, on the basis of them, be true?
The first sentence begins by informing us that planetary bodies vary in what they’re composed of, but most of those in the Solar System have solid surfaces. It may be helpful to think of this sentence in terms of a superset, planetary bodies, and two overlapping subsets, planetary bodies in the solar system and planetary bodies with solid surfaces. The next sentence begins with the conditional indicator unless, and tells us that the renewal of the surface of a planetary body with a solid surface requires enough heat for volcanic activity. This is followed up with another conditional sentence, beginning with the indicator any, that tells that a solid surface planetary body that does not renew its surface will eventually become covered in craters like the moon. The stimulus ends by telling us some of the specifically old planetary bodies in the Solar System, such as Europa, have solid icy surfaces with very few meteorite craters. Interesting!
When we facing a MBT question with lots of conditionals and modifiers such as this one, its important to get a sense of the logic behind the text. We should look for how our conditionals can connect and relate to each other. In this case what we should notice is that if a planetary body doesn’t have a hot enough core, then it must be heavily marked by craters. Since we know some planetary bodies with solid surfaces are icy and not heavily marked by craters, then it must be true that some planetary bodies with icy surfaces have hot enough cores for volcanic activity. Let’s see if any of the answer choices resemble this pre-phrase:
Answer Choice (A) This is a good example of an answer choice where it is important to remember not to bring in outside knowledge to the LSAT. I’m sure many of you know that the moon isn’t icy, but it is still false that this must be true just based off our stimulus.
Answer Choice (B) Remember our different supersets and subsets. We’ve only been told that the renewal requirement applies to specifically solid surface planetary bodies, but this answer choice applies it to planetary bodies as a whole. It’s important to have picked up on the “such a planetary body” referential phrasing in the second sentence to avoid falling for this answer.
Answer Choice (C) We’ve been told nothing about the proportion of solid surface planetary bodies without lots of craters that are icy. For all we know they are all icy.
Answer Choice (D) We are only told about one of Jupiter’s moons, and that it is not heavily pockmarked.
Correct Answer Choice (E) This is exactly what we pre-phrased. If the only way for a solid surface planetary body to not be heavily marked by craters is to be hot enough for volcanic activity, and we’ve been told about a very cold solid surface planetary body that is not heavily marked by crates, then there must be at least some (i.e Europa) very cold planetary bodies with hot enough cores for volcanic activity.
This is a straight forward question stem for an NA question. The argument depends on the assumption in the answer. This is asking for necessity.
First off in this stimulus, that is a powerful sounding book. I don’t know of anything this convincing, so we’ve set a very extreme characteristic to this book. But remember that on the LSAT, we accept the assertions as true. So this book is all powerful in its persuasiveness. Members of the Earth Association gave away 2,000 copies last month. Given its persuasive power, that seems like a worthwhile thing to do for an environmental organization. “Thus” is introducing the conclusion here in the final line: The EA converted 2,000 people to the cause.
Well, a lot of problems might come to mind. First, it’s not enough for someone to own the book to be persuaded by it. It still needs to be read. Did any of these people they gave the books to read it? Also, to be converted, the recipients must not have already been environmentalists. Who are these people? The Earth Association better not have been distributing these at a convention for environmentalists, or I’m skeptical that they haven’t just been handing these out to people who were already environmentalists. Maybe these issues are obvious to some of us, maybe not to others. I do think these are particularly conspicuous compared to the average NA question, but we need not see these as problems. Whether you saw these or not, you still want to keep an open mind with the answer choices. There may very well be something else. With NA, there is almost always other directions a correct answer could take. For example, another NA here would be something like, “Copies of To Save the Earth are not printed in a font too small for any of the 2,000 recipients to read.” Bet no one predicted that, but it would be the right answer if provided. It goes to the same idea that each recipient actually read it, but its presented in a surprising way that may be difficult to recognize if we’re committed to looking for any answer in particular.
Answer Choice (A) Well that doesn’t have to be true. The more the merrier. We might have an issue if other organizations gave it to the same recipients, but this doesn’t say that. If it did, then these people would get this book with or without the Earth Association and so that could be a problem for their claim. If you selected this, did you think that’s what it said? Read carefully!
Answer Choice (B) This is wrong, but it’s a little tricky. Their “willingness” to buy it does not particularly matter. They could both be willing to buy it and not have bought it. I’d be willing to buy lots of things I have not actually bought. So just because they’d’ve been willing to buy it doesn’t mean they’d have obtained (and read) a copy. Furthermore, if they were willing to buy it, it doesn’t at all matter that they would have been willing to have bought it from the Earth Association. Any bookstore or online retailer or yard sale or anything else would be fine. This just doesn’t have to be true.
Answer Choice (C) Recycled paper? No. We might expect this book to be sustainably printed, but this has nothing to do with its persuasive power or whether or not the Earth Association has changed hearts and minds.
Correct Answer Choice (D) Here it is. If someone was already committed to the cause when the Earth Association gave them the book, then the Earth Association cannot claim to have converted that person to the cause they were already committed to.
Answer Choice (E) This is another slippery one. We do need each recipient to convert to the environmentalist cause, but that need not mean they embrace the specific brand of environmentalism advocated for by the Earth Association. That is an additional assumption which we are not at liberty to make and which prevents this answer from being necessary.