PrepTest 137, Section 4, Question 18
Psychologist: Birth-order effects, the alleged effects of when(71 more words not shown)
Which one of the following(8 more words not shown)
- AStandard personality tests(13 more words not shown)
- BThe behavior patterns(15 more words not shown)
- CParents' and siblings'(16 more words not shown)
- DStandard personality tests(12 more words not shown)
- EParents and siblings(11 more words not shown)
Reading the argument
What if the tests simply aren't picking up the effect?
The standard personality tests didn't detect birth-order effects in adults. Family reports did. The psychologist decides that the effect exists only in relatives' perceptions, not in personality itself. But before trusting that explanation, I'd want to know whether the standard tests can detect the relevant effects at all.
We can question the family reports too. Parents and siblings might interpret someone's behavior through expectations about being the oldest or youngest child. Still, finding a reason to question those reports doesn't automatically validate the tests. If the tests miss every real birth-order effect, their failure to detect one tells us little.
What we’re looking for
That gives us the necessary-assumption prediction: the tests would detect something if birth order really affected personality. The argument relies on the absence of a test result to support the absence of a lasting effect, so that detection ability matters.
Working the answers
- ACorrect
If real birth-order effects existed, the tests would detect at least some of them. That is what allows the psychologist to use the lack of detected effects as evidence against their existence.
Imagine a test incapable of detecting any such effect. It would give the same empty result whether birth order mattered or not. Its result couldn't support the psychologist's conclusion. A supplies the required ability to distinguish those possibilities; it doesn't demand that the tests detect every effect perfectly.
- B
People could behave differently with family, but the argument doesn't require that. It says birth order affects how behavior is perceived. The same behavior could be interpreted differently by relatives, without the person actually behaving differently in family settings.
- C
Family perceptions don't have to stay unchanged from childhood to adulthood. They might evolve while still being influenced by a person's place among siblings. The argument needs to distinguish perception from a lasting personality effect, not establish lifelong stability in what relatives think.
- D
The stated tests concern adult personality. Tests of children might find effects or might not, but neither possibility is required by this argument. Finding an effect in childhood would also be compatible with its disappearing later, so D isn't something the adult results settle.
- E
The psychologist doesn't need relatives' perceptions to be accurate. The proposed explanation is that birth order influences their perceptions rather than the person's actual personality. A biased family report could fit that account. Assuming accurate reports wouldn't supply the test-detection ability the argument relies on.
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