Logical reasoning PrepTest 158 · Section 3 · Question 5

As fascinating as it is to contemplate reverse-engineering a wolf by breeding dogs, this argument was not about turning domesticated animals back into wild animals. We're looking for a reason why we can't make every wild species into a domesticated one, not why we can't make every domesticated species into a wild one.

Note the conclusion's scope: any animal could, "in principle," be domesticated. By qualifying the conclusion with the "in principle," the author only claims that it's theoretically possible to domesticate any wild animal. This answer choice points to reasons why domesticating some species would be difficult or time-consuming — the tame members we have to use are more reluctant to mate. However, even if it would take a long time and involve a great deal of cajoling, we could still theoretically breed these species. So this answer choice doesn't undermine the claim that it's theoretically possible to domesticate any species.

Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Weaken

Stimulus Summary:
We've bred domesticated animals by using only the tame members of a wild species. Take dogs: we only bred the tame wolves, and voilà, man's best friend. The author concludes we could, in theory, take any wild animal and produce a domesticated animal.

Strategy Overview:

1. Argument or facts? Always argument, so identify premises and conclusions of argument
2. Anticipate why the premises are not enough to show that the conclusion is true
   1. Causal argument? Look for answer choice that:
      1. Shows possible alternate cause
      2. Shows cause without effect
      3. Shows effect without cause
      4. Shows the cause and effect are reversed
   2. If not causal argument, anticipate ways to worsen problem with argument
3. Use anticipations to select the answer choice that, if true, would weaken argument

Answer Anticipation:
Our ultimate goal is to find the answer choice that weakens the argument. However, it's much easier to do that if we first break down the argument and identify its flaws. Then, weakening the argument is only a matter of finding the answer choice that exploits that flaw.

After breaking down this argument, an experienced test taker will immediately note how strong the conclusion is: "all animals can, in principle, be bred for domesticity." This argument's reasoning is that, since we've successfully bred wild animals like wolves into domesticated animals like dogs by using only the tame members, we could do that with any animal. Domesticated cheetahs, hippopotami, bonobos, grizzly bears … you name it, we can domesticate it (at least in principle).

When we see a conclusion this all-encompassing, certain common flaws will come to an experienced LSATer's mind. One is the Weak Premise flaw. And indeed, that flaw is present here. The premise focuses only on some species that we've successfully domesticated, like wolves. The conclusion, which applies to all species, requires more proof than the weak premise provides. After all, some species may not be as domesticable as wolves. 

This conclusion might also lead a knowledgeable LSATer to think of a Sampling flaw. And that's another way to classify this argument's problem. Indeed, wolves/dogs certainly could be unrepresentative of all species — perhaps many other species are significantly different from wolves, making those other species impossible to domesticate.

Even with a conclusion this overgeneralized, however, we should be careful to note its scope. The author claims that we can in principle domesticate any species. By qualifying the conclusion with the phrase "in principle," the author is saying it's only theoretically possible to make any wild animal into a domesticated species — not that it would be easy, wise, or worthwhile to do so.

No matter how we classify the flaw, we should look for an answer choice that points to why we would not be able to domesticate, even in theory, some wild species as successfully as we domesticated wolves.

Answer Choice Explanation:
This answer choice points out why we wouldn't be as successful domesticating non-lupine species: unlike wolves, some species don't have tame members. As this author's reasoning went, by focusing on just the tame wolves, we created dogs. The author then concludes that by using only the tame members, we could domesticate any wild species. This answer choice points out that some species don't have tame members. Without the ability to select the animals that display tameness, we couldn't necessarily domesticate those species. Therefore, this weakens the author's reasoning and is correct.

Key Takeaway:
Focusing on the scope of the conclusion helps on most argument-based questions in Logical Reasoning. By focusing on how many animals this conclusion applied to (all animals), we could anticipate the flaw in the argument. By focusing on the qualification (we could domesticate any animal "in principle"), we could eliminate some tricky answer choices.

Note the conclusion's scope: any animal could, "in principle," be domesticated. By qualifying the conclusion with the "in principle," the author only claims that it's theoretically possible to domesticate any wild animal. Like (B), this answer choice shows why domesticating some species could be difficult or time-consuming — the tame members are less fertile. However, even if it would take a long time and a great many attempts, we could still theoretically breed these species. So this answer choice doesn't undermine the claim that it's theoretically possible to domesticate any species.

This answer choice gives us a fact about the tameness of domesticated species. However, this author concluded we could domesticate any species by using only the tame members of that wild species. The tameness of domesticated animals doesn't matter to the author's argument, so this answer choice doesn't weaken the argument