Q18 - Certain changes in North American residential

[Laura Damone]

Question Type:
Weaken

Stimulus Breakdown:
Conclusion: Certain changes in North American residential architecture after World War II are attributable mainly to the increased availability and affordability of air-conditioning.

Evidence: Soon after World War II, many builders found that air-conditioned houses lacking the high ceilings and thick walls that traditionally kept residents cool generally sold well.

Answer Anticipation:
This argument has the most common Causation Flaw: explaining a correlation between things by saying that one of them caused the other. The conclusion in this argument also uses a ranking word: "mainly." This means the correct answer could attack the idea that the air-conditioning caused the changes in architecture, or it could attack the idea that air-conditioning was the main cause of the changes in architecture.

Correct answer:
C

Answer choice analysis:
(A) Tempting. This demonstrates a correlation between the architectural features that were changed and different types of severe weather. But in so doing, it doesn't actually establish a causal link. Thus, other types of severe weather aren't presented as a possible alternate cause for the changes made, making this an incorrect answer.

(B) If this is true, it gives folks a good reason to keep the architectural features, not change them! That means this is not an alternate cause for the effect in question. Eliminate!

(C) A counter-example! If the purported effect (low-ceilinged, thin-walled houses) was present in places where the purported cause (air-conditioning) was not, that weakens the claim that the changes in architecture were due mainly to the availability and affordability of air-conditioning. Bingo.

(D) Tempting. When you air-condition a house, do you want the cool air to escape? No way. So this might seem like it weakens the idea that air-conditioning led to thinner walls. However, this claim is relative: Thin walls allow the cool air to escape more readily than thick walls do. But how readily is that? Maybe the thin walls only allow a tiny bit more air to escape, or they only allow it to escape a tiny bit faster. Unless we're told in an absolute way that thin walls are inappropriate for air-conditioned houses, we're not looking at a weakener.

(E) Another tempting answer. Could this be an alternate cause for the changes adopted? Well, there's no cause and effect link expressed here, so no. All we get is another correlation, and without a causal link, we can't call the insulation a potential alternate cause.

Takeaway/Pattern:
While we may think of alternate causes as the gold standard of causal weakeners, we need to be aware of the other causal weakeners, too. Counterexamples, which show the cause without the effect or the effect without the cause, and temporal weakeners that show that the effect may have preceded the cause, are two of the most common!

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