Logical reasoning PrepTest 140 · Section 1 · Question 9

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Methods of Reasoning

Stimulus Summary:
Birth weights in a region over a 50 year period were correlated with crop success, so available food to a mother causes good baby health.

Answer Anticipation:
This stimulus establishes a correlation between two metrics—birth weights and crop success—to determine that the latter is a causal factor in the former. That's a traditional correlation/causation jump, so the correct answer should point out this (flawed!) method of reasoning.

Answer Explanation:
This answer abstractly describes the correlation/causation flaw that the argument falls into. The argument treats the correlation between the success of crops and birth weights as being enough to establish that the former is a causal factor in the latter.

Key Takeaway:
Two takeaways. First, flawed methods of reasoning are still methods of reasoning, so there's some overlap between the Errors in Reasoning and Methods of Reasoning question types. Second, note the answer choices here—they all deal with correlations and/or causation. As you move into the section, questions will get more difficult—one way the difficulty is increased is by making the answer choices closer together. If this were a question #5, there might be only one correlation/causation answer; now that we're at question #9, they all are.

Incorrect. This answer choice does describe a correlation/causation flaw, but it adds in additional language that doesn't reflect the stimulus—"sole cause." The stimulus states that health "depends to a large extent" on food availability, which isn't the same as saying that it's the sole cause.

Incorrect. The argument uses that past correlation to determine that a causal argument still exists today. It also states that, today, food availability is the causal factor, not crop success, suggesting that the correlation from the premise may not still exist today as food availability may come from sources other than crops.

Incorrect. The argument doesn't conclude that a separate factor causes both crop success and birth weight/newborn health, but rather that the former is a causal factor in the latter.

Incorrect. The premise here is a correlation, not a causal relationship, so the argument doesn't infer from a causal relationship.