I haven't taken the test yet either, and I will probably be nervous. It would be nice if I could keep my cat on my lap the whole time. I think that sense of being valued and loved no matter how well I perform would be super helpful. If you are like me then maybe conjuring up a sense of unconditional love before the test would help you too (or maybe sneak in a cat).

Loved the "cat drinking milk" example. More humor like this please.

"But since even this kind of sacrifice is a form of altruism" This tripped me up. For some reason I saw "is" as being an = sign. It's not. "A cat is (necessarily) a mammal" is not the same as "A mammal is (necessarily) a cat." Likewise, "This type of sacrifice is altruistic" does not mean the same as "An act that is altruistic is (necessarily) this particular type of sacrifice. What threw me off is that it was no surprise that self-sacrifice is altruistic. I was surprised in the opposite way: That the author felt it necessary to say so.

@TidyKnowledgeableChocolate I agree. This was a hard question for me and I thought the same about B. It was also hard because the correct answer was obscured. We are trained to be suspicious of self-selection in studies; this question was hard for me specifically because I had graduate courses in study evaluation. Studies are much more scientifically acceptable if groups randomly assigned. Otherwise there may be "something" about the self-selectors that they share in common that contributes to results, and not the drug being tested (in this case the "diet" tested). So the fact that the dieters self-selected is potentially relevant to outcome. Although the purpose of D is to reveal the pilot's reason for their choice, it nonetheless implicitly reiterates the fact that they chose to be in that particular test group.

On the other hand, one might still assert that, regardless of the fact that there is this problem with self-selection, the dieting still seemed to produce a powerful effect on this group. That is because the stimulus says they flew fine before. Therefore, there seems to be support that dieting has that effect even if we eliminate comparison to the other group. But I would argue that D nonetheless still potentially "CONTRIBUTES to an explanation of the results." On the LSAT, I thought there was supposed to be an unequivocally right answer to each question, albeit hard to find sometimes. If so, then I would argue that this does not meet that standard.

@Elijah_Mize I agree with jwn1060 and here is why. The stimulus was: "An arrangement of objects tends to be aesthetically pleasing to the extent that it gives the impression that the person who arranged the objects succeeded at what he or she was attempting to do." "To the extent" is not a conditional, not an if-then, which is all-or-nothing. To see it more clearly, let's change it to: "A golf ball flies to the extent (distance) that it contains rubber in its core." Just like the correlation of impression of success and amount of aesthetic pleasure, there is a positive correlation. Furthermore, it is a causal correlation like the arrangement you argue is reflected in the stimulus. What we can say is that more rubber = more distance, just like more impression = more pleasure. We cannot say "If there is distance then there must be rubber" or vice-versa. If there is no conditional, then there can be no breech of logical validity in the form of sufficiency necessity confusion. Therefore I agree with jwn1060 that JY is in error in citing that as the primary fault in the answer.

@bubbledrop Exactly. It's such an evil trap answer because we all know that anticancer drugs cause people to lose weight because they are nauseous, etc. That has nothing to do with angiogenesis, so it is easy to apply the same idea to rats. I think that the key to getting the right answer is "support." No answer had perfect support, but at least with the correct one you could (albeit imperfectly) refer back to the stimulus for "support."

It was a bit jarring to hear JY so quickly dismiss E as a "terrible answer." I got every single question for all four passages correct except for this one. Furthermore, the comments below frequently cite E, sometimes with the same concerns as mine. Note that some of the other comments below are not directed at question 21. Answer E states the following: "Therefore, the Marcusian critique of advertising is mistaken except in its claim that advertisers exert economic power over those few people who are unable or unwilling to distinguish real from false needs." Notably, we are asked for the "logical" completion of the essay. Answer E was appealing to me because the author of the passage states that "rational" people can resist the pull of advertising and use their own free will. This accounts for "most" people; logically this implies not all. Therefore it follows that there are some who cannot and therefore are not free from the pull of advertising. Then the Marcusian critique (and its implications) could still apply to the people mentioned in E. Notably, the author did not actually disprove it or assert that the Marcusian critique was wrong. They said it was hard to separate real from false and that the assumption that we can do so-- which the Marcusian assumption rests upon-- is "extremely problematic." Furthermore they supported their point with a conditional: "If there is a real need for emotional fulfillment, and if we can freely and authentically choose our means of obtaining it, then free, informed individuals may choose...." Note that this does not say "everyone can choose." Even affirming the antecedent that we can choose freely leaves logical space for Marcuse's critique to still apply. But even given that, look how weak the affirmation is: "This does not mean, however, that consumers do not freely and intentionally use the product as a means to another sort of fulfillment, or even that its genuine fulfillment of needs must be less than the advertisement suggests." The last phrase is the one that concerns us [(I paraphrase): (It does not necessarily follow that people can't achieve satisfaction of real needs)].

In writing this out I realized my mistake. The problem is exactly that the author never fully, logically established that the Marcusian critique is "mistaken." But look at the convoluted and subtle way in which they obscured this! A commenter below said they rejected E because it seemed "too strong," and their instinct was correct. For my part, I disagree with JY's conclusion that E can somehow easily be rejected on its face. I am open to hearing what I may have overlooked and he apparently saw.

I have mostly used the video explanations. However, if I get the question wrong in my 1st try and in my blind review I will look at the light bulb to gain some insight because I am obviously perplexed. I always watch the videos afterwards in those situations. I like the videos because they are in depth and address the reasons why we might make certain mistakes and why wrong answers are tempting. Furthermore, on the more difficult questions there is often a concept in the stimulus that I misunderstood. In making the concepts clear, the video shows that there IS a right answer. Without that assurance I would be more nervous taking the actual test.

It would have been much more helpful to go into the question knowing that there is specific category called "Principle Conform." That category might be considered a derivative of MSS, but the question is made much easier knowing that we are to find the principle in the answer choices that reflects the information in the stimulus. A typical Principle Conform stimulus might ask "The reasoning above conforms most closely to which one of the following propositions?" Of course, in this question we have to replace "situation" with "principle" and "generalization" with "proposition." I must admit that it's a sticky wicket.

@LiviaLSAT Yes I agree. The word "only" should indicate a necessary condition. One is a lawyer only if one has passed the bar exam. A biconditional means necessary and sufficient: One is a lawyer if and only if one has passed the bar exam. If you are a lawyer, you have passed the bar exam, and if you have passed the bar exam then you are a lawyer. But a biconditional doesn't work for that because passing the bar exam doesn't automatically mean you practice law.

Wow this was a tough question for me and I got it wrong. After much analysis I think I got to the crux of the argument and that leads directly to the conclusion. It boils down to the following. The premises are made of condensed information:

P1: Animals have pheromones and their sexual behaviors are involuntary.

P2: Humans have pheromones and their sexual behaviors are voluntary.

C: Pheromones play no role in human sexual behavior.

Obviously the big gap is the assumption that "voluntary" = "pheromones play no role human in sexual behavior," and that is a big assumption. And I got the question wrong because I was thinking pheromones = chemicals; chemicals = control. But the stimulus says involuntary = chemical control... and does not indicate what types and percentages of chemicals (or what ratio of pheromones) combine to result in the right mix of chemicals to produce involuntary action. Therefore, chemicals could be involved in human sexual behavior still, just not to the level of control. The step necessary to bridge to the excessive claim that pheromones play no role whatsoever is "if sexual behavior in humans is voluntary, then pheromones play no role." That is exactly what we find in answer choice B.

My "post-mortem" reasoning devoid of astronomical knowledge was as follows: Assuming there is no other way to measure distance, an observer from Earth sees stars of varying brightness levels. Obviously one could assume the ones that appear dimmer are further away if all things are equal (if all stars had the same intrinsic brightness). But things are not equal. Some stars are inherently brighter than others. So with that let's imagine we see a star that is 25% as bright as the average star. With no way to measure distance, we could assume it was either old and close or young and far. But the key piece of information we need to make that conclusion (younger = brighter) is not in the stimulus. Once we have that we can see that the "earlier estimates" were wrong because they erred too much on the "old and close" side of the formula, so much so that it would make them impossibly old. So correct that to younger/brighter/further and we can make sense. This is actually the second time I have encountered this question. I think I guessed right the first time simply because the conclusion mentions age and distance, a premise establishes a relationship between brightness and distance, so a logical link between the two is age and brightness. I missed the question on my second encounter with it, hence my post-mortem analysis.

I made up a parallel argument to help me see why I got this wrong. Here it is:

A new facility was created to reduce the number of tigers escaping from the local zoo. However, although doing so worked in other cities, it did not work here. Which answer choice does the least to help resolve the apparent discrepancy:

A) The construction crew was later found to have ties to an international tiger theft ring.

B) The zoo's director hates to see tigers locked up; he has the keys and is mentally unstable.

C) The construction crew mistakenly thought the cage was for housecats.

D) Of the tigers that escaped, 75% confessed their guilt.

The last sentence in the stimulus tripped me up. My mind didn't smoothly translate "avoid a decrease" and "not decrease" into its opposite and then link it to "will decrease" while juggling with necessary condition "only if." I think it is partly because there is the added confusion of the mental pair (decrease vs. increase) going against the pair (decrease vs. not decrease). Difficult question.

I do not see the difficulty that J.Y. indicates in the video. Small vacuum tubes are a subset of all vacuum tubes. If no vacuum tubes allow the capacity of electrical current that is necessary to make them preferred, then the necessary condition fails, game over answer A. Perhaps J.Y. misread "current" capacity as "heat capacity at present."?

This is made easier if one uses Venn diagrams. Put "almonds grown in CA" in the center circle. Then each of the concepts "grown for domestic consumption" and "requiring intense irrigation" have to overlap that circle more than 50%. There necessarily has to be some almonds in the overlapping zone.

It is argued by some that I should spend less money on my girlfriend. But let's look at the real cause of my bankruptcy: My gambling problem. Therefore it is not warranted to say that I should spend less money on my girlfriend.