Psychologist: Birth-order effects, the alleged effects of when one was

Question

Psychologist: 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. However, they have been detected in birth-order studies that are based on parents' and siblings' reports of the subjects' personalities. All of these birth-order studies, taken together, show that birth order has no lasting effect on personality; instead, birth order affects merely how a sibling's behavior is perceived.

Which one of the following is an assumption required by the psychologist's argument?

(A) Standard personality tests will detect at least some birth-order effects on personality, if those effects exist. CORRECT.

Which one of the following is an assumption required by the psychologist's argument?

(A) Standard personality tests will detect at least some birth-order effects on personality, if those effects exist.
(B) The behavior patterns people display when they are with family are significantly different from those they display otherwise.
(C) Parents' and siblings' perceptions of a person's personality tend not to change between that person's early childhood and adulthood.
(D) Standard personality tests have detected significant birth-order effects in some studies of young children's personalities.
(E) Parents and siblings have accurate perceptions of the behavior patterns of other family members.

Source: LSAT

generis · Accepted Answer

This question contains an excellent heads up: the word "alleged."

"Alleged" is a descriptor for results of studies,
results this person rejects.

Alleged / studies / results   -- start thinking about   evidence. Hers.

Strong conclusion: 1) birth order has no effect on personality
2) studies that suggest otherwise show only that a sibling's perception changes over time.

Some comments on and highlights of the logic:

1) Standard personality tests have not detected    alleged  to be]   birth order effects on personality.

2)   HOWEVER    , birth order effects on personality have been found in tests that are based       on family members' reports of a subject's personality.

3) "All of these   OTHER"     birth order tests cumulatively demonstrate two things: 
i) "birth order has no lasting effect on personality; and 
ii) birth order affects   MERELY   how a sibling's behavior is perceived."

What must the psychologist be assuming here?

Studies that DO suggest birth-order effects on personality are not good.
"Alleged," coupled with the last sentence's "merely."
gives you insight into her view of the opposition's evidence.

Birth-order studies are both 
different from standard studies and seriously flawed.

Think immediately: if their evidence is flawed, what makes her evidence good?
What IS her evidence?

Her evidence comes from standard personality tests.
Results of these tests: no birth-order effects on personality have been detected.
She assumes the results are accurate. She assumes the tests are good.

These standard studies on which this psychologist relies had better be bulletproof.

Which one of the following is an assumption required by the psychologist's argument?

(A)  Standard personality tests will detect at least some birth-order effects on personality, if those effects exist.

CORRECT.  If you like the negation test, it will work here beautifully. 
 
(In fact, get ready for double negatives, whose use I cannot avoid)

In order to rely on the results of standard personality tests, she must assume that the tests can detect what she claims does not exist.

More specifically, she must assume that the tests CAN catch at least some birth-order effects on personality.

If standard personality tests CANNOT detect at least some birth-order effects, that failure (no results that show birth-order effects on personality) is evidence of nothing.

That failure to detect is not evidence of "zero birth-order effects on personality."

The absence of detection by standard tests DOES NOT PROVE the non-existence of birth-order effects on personalty.
Logic: 
  Person A says: 
Bs do not exist.
Person A uses test T.
If Bs exist, test T can find Bs.
Test T never finds any Bs.
Person A says: "See? I told you. Bs do not exist."

We discover that Test T is not designed to find Bs.
Test T is INCAPABLE of finding Bs.
The claim "Bs do not exist" is based on nothing.

If A is false, the argument collapses.  
 
(B) The  behavior patterns  people display when they are  with family  are significantly different from those they display otherwise. INCORRECT.

This paragraph says nothing about human behavior patterns around family members. 
The subject of this argument is whether or not birth order has an effect on personality.

(C)  Parents' and siblings' perceptions  of a person's personality  tend not to change  between that person's early childhood and adulthood. INCORRECT.

First, to the extent that the subject of the argument includes change over time, the subject is an individual 
("no LASTING effect on   personality"). 
Second, the stability of familial perceptions is not the issue.
The issue is birth order and its effect on personality.

(D) Standard personality tests have detected significant birth-order effects in some studies of  young children's personalities . INCORRECT.

Toss this answer when you see these words:  young children's personalities.  
Her subject is the adult personality 
(she uses the word "adult," and does not mention children). 
If there were ever birth order effects on personality prior to adulthood, 
such effects are not "lasting."

(E)  Parents and siblings have accurate perceptions  of the behavior patterns of other family members. INCORRECT

Whether family members' perceptions are accurate
is not pertinent to her argument about the subject of 
birth order and personality.
 
Answer A.

adkikani · Answer

GMATNinja   generis   VeritasPrepKarishma   GMATNinja two

Is not conclusion talking about BIRTH ORDER studies and option (A) talking about standard personality tests ?

My first evidence is about personality tests conducted on ONLY adults and second evidence is about BIRTH ORDER tests which are conducted on PARENTS + SIBLINGS.

Finally the conclusion talks only about results of BIRTH ORDER tests. How do I interpret if these
include standard personality tests. How do I link both evidences to conclusion?

Option A when NEGATED says:

Standard personality tests will detect NONE of birth-order effects on personality, if those effects exist.

Ok, cool. but what is my conclusion about: Birth order studies, not personality tests.

If I perform PoE on remaining choices:

BEHAVIOR PATTERNS is not discussed in argument, reject this.

PERCEPTIONS - This is nowhere mentioned in argument, rejected.

SOME STUDIES , CHILDREN's PERSONALITIES - Nope , argument is about parents and siblings not children. Rejected.

Whether accurate perception between parents and siblings is present or absent is not my scope of argument.

generis · Answer

adkikani , while I applaud you for taking this question on, this correct answer is really hard to understand by itself. The layers are subtle. We have to think and speak in the context of negation. Proposition X is equivalent to its double negation. Proposition X is equivalent to (not)(not) X.

You found the answer through POE. I understand that you want to get a firm handle on Option A. You are frequently headed in the right general direction. You simply make some wrong turns. In this particular question's context, explaining the correct turns actually gets harder when an answer is partly correct. I cannot follow your thoughts very well here. Is this a question (what is . . .)? Or an assertion? If you are asserting that the conclusion is ONLY about birth order studies, not personality tests, that assertion is not correct. The conclusion includes this argument: Standard personality tests ==> results show NO evidence of birth-order effects on personality ==> there are NO birth-order effects on personality No. The first part of the conclusion and option A are talking about exactly the same thing: standard personality tests. In the prompt, standard personality tests show that birth order does not affect personality . Option A's subject is: standard personality tests. What gives her evidence for the first part of the conclusion? Standard personality tests. Argument 1 in conclusion depends on Evidence 1. Argument 2 in conclusion interprets Evidence 2 (Evidence 2 is poor and irrelevant). The second part of the conclusion dismisses studies that contradict the first conclusion; those not-standard (weird) studies do NOT prove that birth order affects personality. No. Not accurate. Correct, the first evidence is indeed only from standard personality tests conducted only on adults. This evidence supports her conclusion. For her, that supporting evidence is good news. For the reader, that supporting evidence should be the thing to focus on. These words suggest that study evidence is very important: alleged, study, results The second "evidence" is evidence from other , different, NON standard studies. The psychologists thinks these other studies are bad. She calls the researchers' claims "alleged." That is a synonym for unproven. These bad studies do not prove much. They do not prove that birth order has effect on personality. These studies prove MERELY (only) that birth order affects how a sibling's behavior is perceived. What makes these other studies especially bad? These studies are especially bad because they interview family members for perceptions about the subject's personality. Family members' perceptions are not reliable. Family members' perceptions do not prove that birth order affects personality. (These other NON-standard studies are wrong.) Let's say: IF birth order has an effect on personality, we will call that B, for birth order = effect on personality.* Here is the logic, with the negation. Psychologist A says, Bs do not exist. Psychologist A uses test T. If Bs exist, test T can find Bs. Test T never finds any Bs . Person A says: "See? I told you. Bs do not exist." Or: Even if Bs exist, Test T will detect ZERO Bs. If Bs exist, Test T will detect NONE of those Bs. Test T is INCAPABLE of finding Bs. The claim "Bs do not exist" is based on nothing. If her test cannot detect Bs, it can neither prove nor disprove the existence of Bs, and her argument is dead. Highlighted part: No. Per above, Conclusion/Argument 1 <-> Evidence 1 Conclusion/Argument 2 <-> Evidence 2 Conclusion 1 and Conclusion 2 are different. 1 is her main conclusion. 2 is her interpretation of studies that challenge her conclusion. The linkage between conclusions ("arguments") and evidence is different, too, for the two "sets." The conclusion talks about two different things. Birth order is something that happens. Children are born: eldest, middle, youngest. Birth order TESTS are not the same thing as BIRTH ORDER. The first conclusion is "Birth order has no effect on personality." That claim is based on evidence DIFFERENT FROM birth-order studies. Her argument requires this different evidence. This different evidence is not based on very specific birth-order studies, although this different evidence, according to her, does produce facts about birth order. This supporting evidence is . . . what? See my post above. I think you can take it from here. Just please know that there are very few cut-and-dried formulas for the LSAT. What works on CR may or may not work on LR. Sure, many of the tools will help. There is often an "extra step," sort of like what happens in SC. In SC, often you have to step back and consider the meaning of the sentence as a whole. In LR, often you have to step back and consider the argument, its meaning, but most important in assumptions: the argument or conclusion's weak spot. If you have practiced CR (I mean "you" in the generic sense), just know you are smart, these questions are hard, and you have to switch your focus sometimes. If the answer eludes you, try stepping back a little. You understand much more than you realize. The LSAT folks are counting on your confusion. Don't give them the pleasure. Switch your focus from process (rules you have learned) to substance (this argument, which means X, assumes . . . WHAT?) I mentioned that, having taken the LSAT and graduated from law school, these LR questions strike me as different from CR. The stats here show that much. *Here is an example: though studies vary, some common patterns emerge about birth order and personality. Eldest children (or those who assume the role of eldest children) tend toward leadership and self-discipline. Youngest children tend "to be manipulative, social, outgoing, great at sales." Huffington Post, short science article on birth order and personality.

GMATNinjaTwo · Answer

Wow, thank you  generis  for taking on such a difficult post!

adkikani , let us know if you are still confused, and we'll try to help!

gmatexam439 · Answer

Hello  generis , Please point out any wrong in my explanation below. I too arrived at A.

Psychologist: 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. However, they have been detected in birth-order studies that are based on parents' and siblings' reports of the subjects' personalities. All of these birth-order studies, taken together, show that birth order has no lasting effect on personality; instead, birth order affects merely how a sibling's behavior is perceived.

Which one of the following is an assumption required by the psychologist's argument?

(A) Standard personality tests will detect at least some birth-order effects on personality, if those effects exist. CORRECT.

Which one of the following is an assumption required by the psychologist's argument?

-- The conclusion of the argument is that birth order has no effect instead it merely impacts how a sibling's behavior is perceived. The author reaches the conclusion on the basis of 2 tests: personality (that states birth order has no effect) and sibling (that states birth order has effect). When all the tests are taken together the author reaches earlier mentioned flashy conclusion. Now since the author thinks in the direction of personality test we must focus on that.

(A) Standard personality tests will detect at least some birth-order effects on personality, if those effects exist. -- Absolutely matches with our para phrase.  
(B) The behavior patterns people display when they are with family are significantly different from those they display otherwise. -- Even if the pattern are different the tests would be accurate measure of birth order effects. Thus, we can't reach the "flashy" conclusion based on this option. 
(C) Parents' and siblings' perceptions of a person's personality tend not to change between that person's early childhood and adulthood. -- First, we are talking strictly about adults. Second, argument is about "behaviour" and not "personality". 
(D) Standard personality tests have detected significant birth-order effects in some studies of young children's personalities. -- some young children are out of scope 
(E) Parents and siblings have accurate perceptions of the behavior patterns of other family members. --  If this statement were true it would weaken the conclusion because it would contardict the personality test's validity.

generis · Answer

gmatexam439 Nicely done! What I like best about this answer: it is not formulaic. You tracked on the subject of the argument. You figured out the logical connections. You explained the connection among arguments, evidence, and conclusions without jargon as shorthand; the latter sometimes seems more like an assertion than an explanation if issues are complex. There really are no affirmative formulas, no catchy rules, to explain why answer A is correct. You described the context, the arguments, the conclusions, and the evidence in your own words. You nailed it on that front. I have inserted a few words here and there, just suggestions. Your paraphrase is superb. You realized that this question presents a "flashy" conclusion. I assume you mean something such as: bold, hyperbolic, immoderate, or over the top. Yes, her claims will be difficult to sustain. Watch her language and her method as she discredits her opponents. I caught one tiny mistake in the paraphrase, and it may be just phrasing: the standard personality tests are not part of the groups of tests "taken all together" from which she draws her second (and third, really) conclusions. ONLY what you call the "sibling" tests are included in the last two parts of her conclusion. She very nearly mocks the sibling tests. The last two parts of this three part conclusion are somewhat subtle. In effect, she argues that: The sibling studies are not designed to show effects of birth order on personality. The sibling studies test the wrong people. Because they test the wrong people, these non-standard (sibling) studies 1) cannot and do not prove there are birth-order effects on personality, and 2) deliver some fairly useless information about birth order and siblings' perceptions. She notes that the non-standard tests show NO lasting effects of birth order on personality. She implies, almost scornfully, that the bad tests ARE NOT DESIGNED to show such effects because they target the wrong people. When she writes "merely," she hints is a flaw in the methodology of non-standard studies. It's as if she were saying, "DUH. If you study the perceptions of siblings : 1) you are likely to find, if anything at all, a few fairly obvious and irrelevant conclusions about siblings ; and 2) you are not likely to find birth-order effects on personality, because you have no independent corroboration of personality at issue. You don't talk to the most important person! You have no idea what her personality IS, let alone whether or not her personality was affected by her birth order." Answer A says, "DUH. If you use a test that cannot detect the effects of birth order on personality, it will not detect the effect of birth order on personality. The opposite is also true. If your test can detect the effects of birth order on personality, and detects no effects, that is proof: there are no birth-order effects on personality." Answer A's logic is consistent with the logic she uses to criticize non-standard sibling tests. Answer A defends HER test's methodology and design. I think that is what you mean when you say that Answer A "matches the paraphrase." This assumption MUST be true for her argument to hold. This answer shows excellent grasp of the most important thing: the substance of the argument. LR is not mechanical. Rules ("out of scope," "too strong," e.g.) will help -- but in the end, you have to understand what the argument means, and what evidence or assumptions it rests upon. One way to demonstrate such understanding is to write, as here, a paraphrase of the argument. A pleasure to review. Thanks.

gmatexam439 · Answer

generis , Hello generis. Thank you for taking out time and reviewing in detail. I had certainly overlooked a few things such as in option C "lasting" should have been a better way to put forward the detrimental part of the argument. Certainly what you wrote in option A makes complete sense. Sorry, I didn't mean only non standard tests in the paraphrase. Thank you for pointing out that mistake. But I suppose this glitch didn't impact the analysis because the author was afterall trying to demean the non standard tests. Thank you once again.

Neurogenesis · Answer

Here is my take.

Premises=>Psychologist: Birth-order (“BO” hereafter) 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.  
 However, they have been detected in birth-order studies that are based on parents' and siblings' reports of the subjects' personalities.
  
 Conclusion=>All of these birth-order studies, taken together, show that birth order has no lasting effect on personality; instead, birth order affects merely how a sibling's behavior is perceived. 
 
 Which one of the following is an assumption required by the psychologist's argument?

(A) Standard personality tests will detect at least some birth-order effects on personality, if those effects exist.
 
 If such tests do not detect at least some BO effects on personality, if those effects exist, then it cannot be inferred that BO has no lasting effect on personality based on the lack of detection of effects during such tests. The lack of detection would not mean anything in such case. It is therefore required that such test will detect some BO effects if they exist. CORRECT
 
 (B) The behavior patterns people display when they are with family are significantly different from those they display otherwise.
 
 If this is true, then it could call into question the findings of the BO studies. Indeed, people could hide their true self during the personality tests, while they are genuine before their family. This would mean that BO could have lasting effects on personality, there is a possibility that it is not merely a perception of a sibling’s behavior. OUT
 
 (C) Parents' and siblings' perceptions of a person's personality tend not to change between that person's early childhood and adulthood.
 
 Even if such perceptions changed (negation), it could still be merely perceptions affected by BO, without BO having any valid lasting effect on personality. It is not required that perceptions be constant, for the inference that BO has no lasting effect and merely affects family’s perceptions to be true. Perceptions resulting from BO can change while still being merely perceptions. OUT
 
 (D) Standard personality tests have detected significant birth-order effects in some studies of young children's personalities.
 
 If anything that weakens the conclusion that BO has no lasting effect on personality. While such effects would not last onto adulthood (as seen in BO studies using personality tests on adults), BO could still have lasting effect on personality during childhood. This is not consistent with the conclusion and is not our assumption. OUT
  
 (E) Parents and siblings have accurate perceptions of the behavior patterns of other family members.
 
 We know from prompt that reports of family on subjects’ personalities show BO effects. If family had accurate perceptions of the behavior patterns of other members, and assuming such patterns refer to personality, then BO studies involving family reports would in fact show valid lasting effects on personality. It would not be merely family perceptions without any valid effects. If anything, this weakens that BO has no lasting effect. Conversely, negation (inaccurate perceptions) would not change anything to the conclusion. This is not our assumption. OUT

I hope it helps

Psychologist: Birth-order effects, the alleged effects of when one was

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Psychologist: Birth-order effects, the alleged effects of when one was

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