Flawed ReasoningDiff: Medium
Logic Breakdown
Passage Summary: Since butterflies that travel have much lower parasite rates than those that stay put, the author concludes that the act of traveling is what keeps them healthy.
Conclusion: Migration is the primary reason that certain monarch butterfly populations avoid heavy parasite infections.
Reasoning: Non-migrating populations have a 95 percent infection rate, whereas migrating populations have an infection rate of less than 15 percent.
Analysis: This is a classic correlation-versus-causation error. While it's true that migrating butterflies are healthier, the author assumes migration *causes* health. However, it is just as likely that only the healthy, non-infected butterflies are strong enough to survive a long migration in the first place. Look for an answer that suggests the parasites prevent migration, rather than migration preventing parasites.
Conclusion: Migration is the primary reason that certain monarch butterfly populations avoid heavy parasite infections.
Reasoning: Non-migrating populations have a 95 percent infection rate, whereas migrating populations have an infection rate of less than 15 percent.
Analysis: This is a classic correlation-versus-causation error. While it's true that migrating butterflies are healthier, the author assumes migration *causes* health. However, it is just as likely that only the healthy, non-infected butterflies are strong enough to survive a long migration in the first place. Look for an answer that suggests the parasites prevent migration, rather than migration preventing parasites.
Passage Stimulus
Passage Redacted
Unlock Full Passage8.The reasoning in the argument is flawed in that the argument overlooks the possibility that
Correct Answer
D
D presents the reverse-causation/selection effect: if infected monarchs typically cannot migrate, then the group that migrates will naturally have far fewer infected butterflies. The low infection rate among migrants does not show that migration itself helps butterflies avoid parasites.
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