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LSAT Explanations › Preptest 137 › Logical Reasoning › Question 18

LSAT 137 | Section 4 | Logical Reasoning: Q18

LSAT Preptest 137 explanations

LR Question 18 Explanation

QUESTION TEXT: Psychologist: Birth-order effects, the alleged effects of…

QUESTION TYPE: Necessary Assumption

CONCLUSION: Birth order has no lasting effect on personality. It just affects how others perceive your personality.

REASONING: Birth order studies that rely on others’ impressions show that birth order has an impact. Birth order studies that use regular personality tests don’t show an impact.

ANALYSIS: The conclusion makes a valid distinction between how your personality is and how others see your personality. Fact and perception are different things.

However, the author hasn’t proven their argument. They’re assuming that all the studies are valid. But we don’t know anything about these studies. Maybe all the studies that use standard personality tests are flawed.

___________

  1. CORRECT. If this isn’t true, then standard personality tests are completely useless for studying birth order effects. They couldn’t detect any effects. So the studies cited in the stimulus would be worthless.
  2. This makes no difference. If you behave differently around your family, then that’s just part of your personality, and it can be studied.
  3. This is irrelevant. We only care if birth order affects perceptions. It doesn’t matter if those perceptions change over time. It makes sense that they would, since your personality changes over time.
  4. The conclusion says that birth order has no lasting effect on personality. So it doesn’t matter if there is an effect in childhood, as long as that effect disappears before adulthood.
  5. We don’t care if perceptions are accurate. We only care if these perceptions (accurate or not) are affected by birth order.
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Comments

  1. Maya- Bella says Member

    July 31, 2018 at 7:06 pm

    HI! I’m still unsure as to why A is correct. It doesn’t make sense to me that “standard personality tests must detect at least some birth- order effects,” when the first sentence in the stimulus states the opposite. I must be reading the stimulus improperly. I can deduce that it’s the proper choice because the other answers don’t make any sense, but I want to make sure I understand the concept. Thanks so much!

    Reply
    • Lucas (LSAT Hacks) says Tutor

      August 3, 2018 at 3:38 pm

      There’s an important distinction between the first sentence of stimulus and (A).

      (A) is saying that if birth order effects personality, standardized personality tests will detect at least some of those effects.

      The first sentence of the stimulus, on the other hand, is just saying that birth order effects have not been detected in these tests. This fact has nothing to do with the capability of these tests to detect birth order effects. If we just look at this sentence on its own (that is, without looking at (A)), we still can’t say anything about whether the tests are capable of detecting the effects.

      Reply

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