Q18 - Doctor: Angiotensinogen is a protein

[ohthatpatrick]

Question Type:
Flaw

Stimulus Breakdown:
Conclusion: X is a cause of high blood pressure.
Evidence: X causes an increase in angio, and angio is correlated with high blood pressure.

Answer Anticipation:
The author is thinking "X causes angio to go up, and [assumption: when your angio goes up, you get high blood pressure], thus X is a cause of high blood pressure."

This is the most classic argument template:
PREMISE = curious fact / correlation / change
CONCLUSION = explanation for / interpretation of that premise.

Here, we've got
CURIOUS CORRELATION: Higher Angio is correlated with Higher Blood Pressure.
AUTHOR'S INTERPRETATION: Higher Angio CAUSES Higher Blood Pressure.

We always address this classic template with the same two questions.
1. Is there some OTHER WAY to explain the Curious Fact?
2. How PLAUSIBLE is the Author's Explanation?

Here, that means:
1. Is there some OTHER WAY to explain why Angio and HBP are correlated? (such as reverse causality: HBP actually causes high Angio or third factor: the same genes that give rise to high angio also give rise to high BP)
2. How PLAUSIBLE is the interpretation that high angio CAUSES high blood pressure?

On a Strengthen/Weaken question, we'd have to worry about both types of answers. On Flaw/Nec Assump, they are almost always just testing the #1 ideas, or on Flaw, they just simply test the idea that we went from correlation to causality.

Correct Answer:
C

Answer Choice Analysis:
(A) This describes the Conditional Logic flaw. There was no conditional logic in the evidence. Eliminate.

(B) We are NOT willing to grant the author that "high angio CAUSES high blood pressure", so an answer saying "even if one thing DOES cause another" is not what we want.

(C) YES. Because "high angio" is correlated with "high bp", the author assumes that "high angio LEADS TO high bp".

(D) Close, but the author "assumes that one phenomenon causes a second without ruling out the possibility that the second phenomenon causes the first".

(E) The last part of this is supposed to reflect the conclusion, but the conclusion is not saying that "Disease X can NEVER be the cause of high blood pressure" (in fact, it concludes the opposite).

Takeaway/Pattern:
They're busting out their most classic trope: Correlation vs. Causality. How are they going to disguise it to make it difficult?

First of all, the evidence DOES involve genuine causality, in that X does cause higher angio. What we're concerned with is the implicit causal assumption makes that "higher angio causes high blood pressure".

Secondly, the real answer is a simple, unvarnished "correlation vs. causality", while (B), (D), and (E) sound so confusing that people might be persuaded into picking them because they don't understand them enough to know why they're wrong.

#officialexplanation

[letslsat]

"We are NOT willing to grant the author that "high angio CAUSES high blood pressure"

Why can't we grant the conclusion in answer choice B?

[ohthatpatrick]

Because all we know is that high angio is CORRELATED with higher blood pressure.

Correlations suggest there might be causality, but they don't establish it as a fact.

Fighting against the author's assumption that "high angio CAUSES higher blood pressure" is the whole point of this question. LSAT wants us to attack that assumption, not grant it.

[andrewgong01]

For "even if " language in "B" on the LSAT would we ever want to grant the author the benefit of the doubt and say "even if what you said was true you are still wrong"? I don't recall seeing Even IF that often but I came across another "Even if" choice last week and I believe the explanation for that one was along the lines of how it does not matter if it is true

[JH388]

Hi all,

I'm having trouble with this particular question. To me, saying "The higher A is, the higher B is" implies a causal connection in idiomatic English. I narrowed this question down to B and C and ruled out C based on this understanding.