Self-study
Psychologist: Support Birth-order effects, the alleged effects of when one was born relative to the births of siblings, have not been detected in studies of adult personality that use standard personality tests. ████████ ████ ████ ████ ████████ ██ ███████████ ███████ ████ ███ █████ ██ ████████ ███ █████████ ███████ ██ ███ █████████ ██████████████ ███ ██ █████ ███████████ ████████ █████ █████████ ████ ████ █████ █████ ███ ██ ███████ ██████ ██ ████████████ ████████ █████ █████ ███████ ██████ ███ █ █████████ ████████ ██ ██████████
Summary
The author concludes that the order in which a sibling is born in a family doesn’t affect personality; rather, it affects only the perception of that sibling’s personality.
What makes the author think this?
Because alleged birth-order effects on personality have not been detected in studies that use standard personality tests.
However, they have been detected in studies based on parents’ and siblings’ reports about the personalities of siblings.
Notable Assumptions
The author assumes that the fact birth-order effects have not been detected in studies that use standard personality tests proves that those effects do not actually exist. (This overlooks the possibility that the effects still might exist, even if studies haven’t been able to prove their existence.)
The author also assumes that the effects found in studies based on parents’ and siblings’ reports do not reflect actual features of a siblings’ personality, but only differences in how that personality is perceived.
18.
Which one of the following ██ ██ ██████████ ████████ ██ ███ ██████████████ █████████
a
Standard personality tests ████ ██████ ██ █████ ████ ███████████ ███████ ██ ████████████ ██ █████ ███████ ██████
Necessary, because if it were not true — if standard personality tests MIGHT NOT detect birth-order effects on personality even if those effects exist — then the fact that studies using standard personality tests have not found birth-order effects would not establish that those effects do not exist. In other words, the negation of (A) opens the possibility that the effects DO exist, despite the failure of studies based on standard personality tests to prove their existence.
b
The behavior patterns ██████ ███████ ████ ████ ███ ████ ██████ ███ █████████████ █████████ ████ █████ ████ ███████ ██████████
Not necessary, because the argument doesn’t depend on any comparison between how people behave with family than with non-family. Even if people behave very similarly, that doesn’t change how we interpret any of the birth-order studies cited and it doesn’t change whether those studies provide evidence of the lack of birth order effects.
c
Parents' and siblings' ███████████ ██ █ ████████ ███████████ ████ ███ ██ ██████ ███████ ████ ████████ █████ █████████ ███ ██████████
Not necessary, because even if family members’ perceptions of a person’s personality do tend to change as that person grows up, that doesn’t suggest that birth-order might have some effect on personality. There could still be no actual effect on personality, only an effect on how family members’ perceive the person’s behavior.
d
Standard personality tests ████ ████████ ███████████ ███████████ ███████ ██ ████ ███████ ██ █████ ██████████ ██████████████
Not necessary, because the conclusion concerns whether birth order has a “lasting” effect on personality. Whether there might be some detectable effect in young children doesn’t change that fact that we have evidence that these effects do not exist among adults.
e
Parents and siblings ████ ████████ ███████████ ██ ███ ████████ ████████ ██ █████ ██████ ████████
Not necessary, because birth order can still impact how a person’s behavior is perceived, even of those perceptions are not accurate. For example, family members might perceive a sibling has getting angry whenever he’s served last at dinner; in reality the sibling might not get angry every time he’s served last. Regardless of the reality, the family members have a certain perception and that perception can be influenced by the person’s birth order.