#20 - Scientist: Given the human tendency to explore and

[Administrator]

Complete Question Explanation

Method of Reasoning. The correct answer choice is (D)

This scientist discusses the hypothesis that humans’ natural tendency to colonize will eventually lead
to galaxy-wide colonization by trillions of humans. That number of humans is so great that were
this to happen, the vast majority of humans ever to exist would live during this period. Since we are
representative humans, it would be exceedingly likely that we would be alive during such a period,
but we are not. The author concludes that galaxy-wide colonization is thus unlikely to occur.

Premise: Trillions of humans would comprise the vast majority of humans to ever exist.

Premise: As humans, we have no reason to think we are unrepresentative.

Subsidiary conclusion: Thus it is extremely likely that we would be alive during this period
as well.

Premise: We are not alive during that period.

Main Conclusion: It is unlikely that such colonization will ever take place.

The stimulus is followed by a Method of Reasoning question, so the correct answer choice will
describe the scientists’ reasoning process.

Answer choice (A): The scientist’s conclusion is not based on the fact that trillions of humans have
never existed before, so this choice’s description of the author’s reasoning is inaccurate, and this
choice should be ruled out of contention.

Answer choice (B): This answer choice describes an argument that is self-contradictory. Since there
is no implied contradiction to any premise that the author has accepted, this cannot be the correct
answer choice.

Answer choice (C): The author actually makes a prediction about the future based on present facts,
so this choice cannot provide an accurate depiction of the scientist’s reasoning.

Answer choice (D): This is the correct answer choice. The scientist says that the existence of
trillions of humans would make it very likely that we as humans would be alive during that period.
Since that is not the case (that event has not occurred), the author believes that the hypothesis is
probably false.

Answer choice (E): The theory that the scientist refutes is based on the human tendency to explore
and colonize. The scientist’s argument is based not on established human tendencies but on statistics.

[maximbasu]

Hi,
The correct answer is D while I chose A.

I understand how D is correct; you're rejecting the hypothesis of colonization.

Why is A wrong? You could reason that since the prospect of colonization didn't occur, the author is saying that the event has a low probability of occurring.

Rgs,
Maxim

[David Boyle]

Hi,
The correct answer is D while I chose A.

I understand how D is correct; you're rejecting the hypothesis of colonization.

Why is A wrong? You could reason that since the prospect of colonization didn't occur, the author is saying that the event has a low probability of occurring.

Rgs,
Maxim

Hello Maxim,

Answer A talks about a specific event, but the stimulus doesn't discuss that. The stimulus just says, fallaciously, that since most humans may be alive during the huge future period of time including star colonization, and since we're not unrepresentative and so should statistically likely be alive during that future period (!!!), that since we're not alive during that future period, star travel isn't going to happen. Quite a stretch.
(If you want to call our not being alive in the future the "specific event", then it's the star colonization that is said to have a low chance of occurring, not our being alive in the future, which has already been established to be impossible.)

Hope this helps,
David

[15veries]

Hi,
I was not sure about the language in D.
It says "false" but in the stimuls it only says "the odds are slim."
Are those two interchangeable?
I thought subtle language shift like this is very important and sometimes because of changes like this can make an answer choice wrong.
When are two different words interchangeable?

[Emily Haney-Caron]

Hi 15veries,

This really comes down to taking the words in context, and not isolating them. You want to think about the meaning, not just the plain language of individual words. As part of this, keep in mind that it isn't "false," but rather, "probably false," and in context D is the best answer even if it isn't a perfect answer. Take a look again, thinking through the meaning as a whole, and see if it makes a bit more sense.

[Rita]

Answer A talks about a specific event, but the stimulus doesn't discuss that. The stimulus just says, fallaciously, that since most humans may be alive during the huge future period of time including star colonization, and since we're not unrepresentative and so should statistically likely be alive during that future period (!!!), that since we're not alive during that future period, star travel isn't going to happen. Quite a stretch.
(If you want to call our not being alive in the future the "specific event", then it's the star colonization that is said to have a low chance of occurring, not our being alive in the future, which has already been established to be impossible.)

Hope this helps,
David

Hi David,

I don't understand this reasoning. Answers A and D both reference 'an event,' which I took to be colonization of the galaxy. A says that because colonization hasn't occurred, it probably won't occur. D says that because there's a hypothesis that colonization will occur, and colonization hasn't occurred, the hypothesis is probably false. But the premise more strongly supports A, because it specifically states that "the odds are slim that such colonization will ever happen". Could you please explain why D is still the better answer? Also, is it normal LSAT language to call the beliefs of some people "hypotheses"? I believe a lot of things that I probably wouldn't call hypotheses, so that threw me off.

Thanks,
Rita

[Jonathan Evans]

Hi, Rita,

By "hypothesis," the LSAT means "a proposition made as a basis for reasoning, without any assumption of its truth." In other words, a "hypothesis" is a conjecture, speculation to be either accepted or refuted based on what the evidence demonstrates.

Let's describe what's going on in this argument:

Hypothesis: Some people claim that galaxy will eventually be colonized by trillions of humans.

P1: If this colonization were to occur, the majority of humans ever to live would be alive during this period (okaaaay yeah I guess based on the validity of this hypothesis, this would be a reasonable inference)

P2: We are all humans and are likely taken as a group representative of humans.

Intermediate Conclusion: The odds are overwhelming that we would be alive during this period (Error in the use of evidence fallacy: No actual evidence that we should be alive during the future)

Main Conclusion: Since we are not alive during colonization, colonization will likely never occur (Even granted the validity of the invalid Intermediate Conclusion, the Main Conclusion introduces a new minor assumption that we will not in fact be alive during this period)

This "argument" is ridiculous, but we have to describe it: The author argues against the validity of a given hypothesis based on specious reasoning about evidence that purportedly opposes it.

This is a match for Answer Choice (D).

Answer Choice (A) on the other hand just reduces the argument to a different structure, that because colonization hasn't happened yet, it won't happen. That's not actually the argument. The argument is that we would almost certainly be alive during colonization were it to happen, and since we're not alive during colonization it won't happen.

You must be very precise in your analysis of these problems and make sure you have a complete match between what the answer choice describes and the structure of the argument in Method of Reasoning questions.

[Rita]

That was really helpful, thank you!

[bli2016]

Hi, the stimulus for this question was incredibly confusing to me and I am still having a hard time figuring out why D is correct. My understanding of the stimulus is this:

Background info: Some people think that the galaxy will eventually be colonized by humans because humans have the tendency to explore and colonize new areas.

Argument:
P) If the galaxy is colonized, then the vast majority of humans would be alive during this period.
P) We are humans and we are representative
P) We will not be alive during this period
C) Odds are slim that colonization will occur

Ultimately I understood the conclusion as a contrapositive of the first premise (vast majority of humans not alive --> galaxy is not colonized). That made me very confused because I saw the stimulus as having circular reasoning.

Also, I had trouble distinguishing what the "event that is taken to be likely" in answer choice D is. Is the event the premise that humans will be alive during this period of colonization or that the galaxy will be colonized, as given by the first sentence?

Seems like I need a lot of help here-- Thanks in advance!

[Kristina Moen]

Hi Bli,

The stimulus is confusing because it is a flawed argument! So it's a good thing that you're confused and questioning what you just read. Keep those instincts.

Keep in mind that the conclusion here is "the odds are slim that such colonization will ever happen." It is acceptable to use the contrapositive of a premise to support a conclusion. We often call that a counter-premise. Here's the simple structure of this argument: "Some people think A will happen... but if A were to happen, then B would happen. But B won't happen, so A can't happen." There is a flaw here, and that is in the author's explanation of why "B won't happen" (this part: "Since all of us are humans and we have no reason to think we are unrepresentative, the odds are overwhelming that we would be alive during this period, too. But, because we are not alive during this period...").

But thankfully, this question doesn't actually address that flaw. We just want to know what happens in the argument. Here, "event that is taken to be likely" is that "the vast majority of humans ever to live would be alive during this period of colonization." But the author concludes that this has not occurred (since we're not alive during this future period), so the hypothesis that humans will colonize the galaxy is probably false.