Logical ReasoningDifficulty: Easy

PT134 S2 Q2 Explanation

Psychologist: A study of 436 university students

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsFlaw

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Stimulus

Psychologist: A study of 436 university students found that those who took short naps throughout the day suffered from insomnia more frequently than those who did not. Moreover, people who work on commercial fishing vessels often have irregular sleep patterns that include frequent napping, is very likely that napping tends to cause insomnia.

What this question is testing

Flaw

Your task

Describe the reasoning error the argument actually commits.

Common trap

Answers that name a real logical flaw the argument doesn't actually make.

Winning move

Articulate the gap in the reasoning yourself, then match it to the choice that describes that gap.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
2.

The reasoning in the psychologist's argument is most vulnerable to criticism on the grounds

Answer choices

  1. Out of Scope0% picked this

    presumes, without providing justification, that university students suffer from insomnia more frequently than do members

    The correlation between napping and insomnia is identified by comparing students who suffer from insomnia with students who do not. The general population is not relevant to the argument.

  2. Too Strong14% picked this

    presumes that all instances of insomnia have the

    The argument does not go so far as asserting that all instances of insomnia are caused by napping.

  3. Wrong Flaw0% picked this

    fails to provide a scientifically respectable definition for the

    The argument never confuses the meaning of the term "napping."

  4. Correct85% picked this

    fails to consider the possibility that frequent daytime napping is an effect rather than a

    Why this is right

    Correlation does not imply causation, and so while it is possible that napping causes insomnia, the reverse is also just as likely.

    Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.

  5. Wrong Flaw1% picked this

    presumes, without providing justification, that there is such a thing as a regular sleep pattern for someone working

    The second premise does not use a relative comparison, unlike the first premise. So the argument does not assume there is a regular sleep pattern for someone working on a commercial fishing vessel.

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