Good stuff here so far, guys! I like it!
Your conversation drew my attention to this particular question, and I find it interesting so I'm going to add my thoughts to the mix as well
This is a tricky—no surprise given that it's #20—Flaw in the Reasoning question, where the author makes a number of questionable assumptions in drawing the conclusion.
So let's start by determining what the conclusion is, and look at the reasoning/evidence used to see if we can figure out what's wrong here!
The author believes that citizens are becoming increasingly disconnected from politics/voting with each passing generation. Why does the author think people are losing interest from one generation to the next? Because people over 65 vote with the greatest frequency (highest voting percentage per age group) while young adults are least likely to vote (of all age groups young adults vote least frequently). So the author is attempting to explain, to provide a cause for, why voting frequency is lower among young people than senior citizens: younger people are more disconnected from politics than older people, and it's progressive (meaning as you go younger, the disconnect becomes larger).
In other words with each successive generation people are becoming less and less likely to vote, which indicates a disconnect with the political system. What would the author expect of the
next generation? An even lower voting percentage. And the one after that? Lower still.
But, as we should always be doing on this test, let's begin to question what might be wrong with this belief. To do so, all we're really looking for is anything we could say that might lead to an alternative interpretation of the facts given. A conclusion different from the author's, but that could still theoretically be true based on what we know.
With causality one of the easiest ways to challenge it is to consider alternate causes. What else, besides a growing disconnect among younger and younger voters, might explain the voting frequency increase with age? Could be lots of thing! For instance, perhaps people inclined to vote tend to live longer than non-voters, meaning by the time people are 65 and over their ranks are better populated with voters...not because younger generations care less or are indifferent, but simply because of the selection process where voting increases survival rates.
Or, alternatively, maybe the older generation just grew more and more invested in voting as time went on (the older they got), and the same thing will happen to the young adults the author mentions too! That is, it might not be that the young adults who don't vote as often are less connected than the previous generation (who are now older and vote more); it could instead be that the current young adults will vote more and more frequently as they grow older, and then from generation to generation nothing has changed. In short, the author seems to have potentially confused the behavior of "generations" with that of just "age groups."
So what you'd really want to do to make the author's conclusion better would be to compare how these now-old voters behaved when
they were young adults to how today's young adults are behaving (their voting patterns). That's a much more reliable way to see if things are changing generationally: compare two different generations at their same stage in life! Young adults in the 2010s to young adults in the 90s to young adults in the 70s and so on. If you found that successive generations of young adults did indeed vote less and less frequently, then the trend the author is assuming carries more weight. We still wouldn't know the for-sure cause, of course, but at least our evidence would be more trustworthy. What we see in this argument on the other hand could just be a symptom of growing older and more responsible or gaining a greater sense of civic duty or whatever.
To put it in the form of an analogy, it would be like me saying this: "I'm currently a junior in college and my little sister is in 4th grade. The amount of time my friends and I devote to our academics is WAY greater than what my sister and her friends do. Seems this younger generation clearly doesn't have the same work ethic that my generation has." Silly,right? A better—not perfect, but better—comparison would be looking at what I was doing in 4th grade years ago vs what she's doing now, or waiting until she's a junior in college and comparing that to what I'm doing now. But comparing two different groups at vastly different stages in life and attempting to draw conclusions on the basis of the same type of behavior is pretty much impossible.
In short: bad argument.
We need an answer then that outlines the mistake the author has made, where "generations" aren't being compared in a way that makes much sense.
Answer choice (A) is the correct answer for precisely that reason. The issue here, again, is that the author is comparing "generations" at entirely different stages in their lives, allowing the cause for different behavior to be growing older rather than some external force like feeling disconnected from the political system.
Answer choice (B) is irrelevant, since this is not an argument about numbers (group sizes). This argument is about percentages (frequency), so the size of the groups doesn't matter. We just care about the proportion of each group that votes. This is a fairly common numbers and percentages idea on the LSAT.
Answer choice (C) is not an accurate description of the facts here, since the whole point of this argument is to provide an explanation: a smaller percentage of young adults vote because they have become increasingly disconnected from the political system. That's the explanation provided for the phenomenon of voting percentage differences, so (C) is factually false.
Answer choice (D) describes a reverse causation error, which does not occur. This would be something like the author stating "we've found that young adults vote the least and also report the greatest sense of disconnect from politics...so it seems the less frequently you vote the more disconnected you feel!" Ummm, no, probably the reverse of that: feeling disconnected causes you to vote less frequently, not the other way around.
Of course, the author never does anything like that, so (D) is out.
Answer choice (E) is also factually incorrect: the author clearly —expects voting patterns to change in the future, as we're told that citizens "are becoming" more disconnected; that means the author expects future generations to vote at even lower percentages that today's young adults. So that possibility is definitely not overlooked.
Note too for (E) that even if this statement was true about the stimulus it still wouldn't necessarily be the
Flaw in the argument. You can say a lot of accurate things about an argument and fail to describe what's wrong with it: the author overlooks the possibility that the legal voting age may one day change, this argument fails to be more than two sentences long, etc. Those are true. But they aren't the reason for skepticism.