Q5 - Taste buds were

[smiller]

Question Type:
Flaw

Stimulus Breakdown:
Premise: Food that tastes sour or bitter might be harmful to humans.
Premise: Early humans recognized a sweet taste or salty taste as a sign of nutrition.
Conclusion: This ability to test food using taste completely explains why people clearly distinguish these four tastes.

Answer Anticipation:
"Completely" explained? Wow. Any time the LSAT uses language this strong in a conclusion, be suspicious. The premises will have to provide strong support for this conclusion by ruling out the need for any other explanation.

Correct answer:
(E)

Answer choice analysis:
(A) Wrong Flaw: Be careful with this one. You might think that "sufficient to justify the conclusion" relates to "completely explained." That might be a good enough reason to defer on this answer choice at first, but on closer inspection this doesn't hold up. Answer (A) is describing a conditional logic error. An example of that would be something like, "if a food tastes bitter, it might be poisoned. This food is poisoned. Therefore, it tastes bitter." The conclusion in this example doesn't follow logically from the premises. If you don't understand why that is so, you should read our Logical Reasoning Strategy Guide, and possibly some good murder mystery novels.

(B) Not a Flaw: If some people associate food with smells more than taste, that doesn't interfere with our argument. This isn't something that the argument needs to consider.

(C) Not a Flaw: This could possibly provide support for our premises, if the foods mentioned in this answer were poisonous when raw but not when cooked. But we don't even know if that's the case, and this fact wouldn't interfere with our argument. It's not something that the argument needs to consider.

(D) Not a Flaw: If early humans ate a more limited range of foods than we do, perhaps they didn't encounter bitter foods, or sweet foods. That might hurt the argument, but it's a whole lot to assume, and nothing in choice (D) really leads us toward that specific assumption.

(E) Correct: This answer describes the flaw quite neatly. It mentions a "complete explanation," which matches the conclusion of our argument, and describes the evidence as something that might only serve as a partial explanation.

Takeaway/Pattern:
Strongly worded conclusions require strong support. Also, in order to be correct, an answer choice that refers to something that the argument "fails to consider" needs to describe a significant objection to the argument, something that would pose a serious threat to the argument's reasoning.

#officialexplanation