Juvenile monkeys that are separated

[as2764]

Juvenile monkeys that are separated from their mothers will often show self-destructive behavior, such as picking at their fur or refusing to eat. These behaviors are the most prevalent in monkeys that are caged alone, are somewhat less prevalent when the monkeys are caged with other, unrelated juveniles and adult males, and are the least prevalent, but still observable, when the monkeys are caged with a mixed-gender group of unrelated, adult monkeys.

Which of the following hypotheses best explains the phenomenon described above?
a. The presence of unrelated juvenile and adult male monkeys causes more self-destructive behavior in juvenile monkeys than does the presence of a mixed-gender group of unrelated adult monkeys.
b. The presence of unrelated adult female monkeys is more important to juvenile monkeys in alleviating distress caused by being separated from their mothers than is the presence of unrelated juvenile monkeys.
c. The presence of unrelated adult male monkeys is threatening to juvenile monkeys, causing self-destructive behavior similar to that caused by the separation of juvenile monkeys from their mothers.
d. The presence of unrelated adult female monkeys serves as a suitable substitute for a juvenile monkey’s mother following a separation from the mother.
e. Juvenile monkeys that display self-destructive behavior will engage in this behavior the least when reunited with their mothers, and will engage in this behavior slightly more when caged with adult female monkeys who are not their mothers.

i chose d, because it says that the presence of unrelated adult females serves as a suitable substitute, while i think that b is very strong in saying that the presence of unrelated adult female monkeys is important.

can an instructor please help me understand?

[jnelson0612]

Juvenile monkeys that are separated from their mothers will often show self-destructive behavior, such as picking at their fur or refusing to eat. These behaviors are the most prevalent in monkeys that are caged alone, are somewhat less prevalent when the monkeys are caged with other, unrelated juveniles and adult males, and are the least prevalent, but still observable, when the monkeys are caged with a mixed-gender group of unrelated, adult monkeys.

Which of the following hypotheses best explains the phenomenon described above?
a. The presence of unrelated juvenile and adult male monkeys causes more self-destructive behavior in juvenile monkeys than does the presence of a mixed-gender group of unrelated adult monkeys.
b. The presence of unrelated adult female monkeys is more important to juvenile monkeys in alleviating distress caused by being separated from their mothers than is the presence of unrelated juvenile monkeys.
c. The presence of unrelated adult male monkeys is threatening to juvenile monkeys, causing self-destructive behavior similar to that caused by the separation of juvenile monkeys from their mothers.
d. The presence of unrelated adult female monkeys serves as a suitable substitute for a juvenile monkey’s mother following a separation from the mother.
e. Juvenile monkeys that display self-destructive behavior will engage in this behavior the least when reunited with their mothers, and will engage in this behavior slightly more when caged with adult female monkeys who are not their mothers.

i chose d, because it says that the presence of unrelated adult females serves as a suitable substitute, while i think that b is very strong in saying that the presence of unrelated adult female monkeys is important.

can an instructor please help me understand?

Ashish,
Sure, let's examine what is going on here. When juvenile monkeys are separated from their mothers, they show self-destructive behavior.

1) The behavior is the worst when monkeys are caged alone.
2) It still exists but is not quite as bad when monkeys are caged with other unrelated juvenile monkeys and adult males.
3) It still exists but is even less prevalent when monkeys are caged with other unrelated adult male and female monkeys. ("These behaviors are . . . the least prevalent, but still observable, when the monkeys are caged with a mixed-gender group of unrelated, adult monkeys")

So which answer choice best explains the result? Let's compare:
B-The presence of unrelated adult female monkeys is more important to juvenile monkeys in alleviating distress caused by being separated from their mothers than is the presence of unrelated juvenile monkeys.
YES. Compare 2 to 3. The monkeys had fewer signs of distress when with the adult male and females than with the juvenile and male monkeys.

D-The presence of unrelated adult female monkeys serves as a suitable substitute for a juvenile monkey’s mother following a separation from the mother.
NOT AS GOOD. The distress behaviors still continue in the presence of the unrelated adult female monkeys, so it's harder to say that they are a "suitable substitute".

Hope this helps!

[as2764]

Jamie, B and D are quite subtle. now that you mentioned the choices, i paid closer attention to the bolded words:

(B)The presence of unrelated adult female monkeys is more important to juvenile monkeys in alleviating distress caused by being separated from their mothers than is the presence of unrelated juvenile monkeys.

i re-read this as the presence of X is more important to Y than is Z
i still contend that this is somewhat convoluted, and could be better said as X is more effective in alleviating Y's stress than is Z.
i feel that the word important is confusing than saying effective, soothing or relaxing.

(D)The presence of unrelated adult female monkeys serves as a suitable substitute for a juvenile monkey’s mother following a separation from the mother.

so this is wrong, because it says adult females can act as juvenile males' mothers -- an absolute replacement.

thanks!

[jnelson0612]

Exactly ashish, very good work!

[jainishsurana]

Can someone please explain that why is A wrong?

[jnelson0612]

Can someone please explain that why is A wrong?

A says: The presence of unrelated juvenile and adult male monkeys causes more self-destructive behavior in juvenile monkeys than does the presence of a mixed-gender group of unrelated adult monkeys.

The whole passage is about the behavior of juvenile monkeys when separated from their mothers. That is a very important distinction. A is saying that juvenile monkeys being with one group causes more self-destructive behavior than when they are in the other group--but is that true if the mother is also in the cage with the juvenile? The mother's absence is critical in having this effect and must be mentioned in the correct answer choice.

[sachin.w]

Hi ,
I took a crazy 4.05 mins to get to the rigth answer. Part of the problem is I couldn't identify that this was a explain the discrepancy Qs.
but still Is this much time justifiable for a Qs of this complexity?
Regards,
Sach

[tim]

that's a little beyond what i would consider acceptable in terms of timing. you will want to work to get faster on these, and a big part of that is correctly identifying what the question is asking for..

[keenys]

2) It still exists but is not quite as bad when monkeys are caged with other unrelated juvenile monkeys and adult males.
3) It still exists but is even less prevalent when monkeys are caged with other unrelated adult male and female monkeys. ("These behaviors are . . . the least prevalent, but still observable, when the monkeys are caged with a mixed-gender group of unrelated, adult monkeys")

Hello Instructors,

The difference between 2) and 3) is the presence of female monkeys.

However, the answer choice B says that the "The presence of unrelated adult female monkeys is more important to juvenile monkeys ****** than is the presence of unrelated juvenile monkeys."

However, this does not sound true. Is it not that the presence of female monkeys is more important than the presence of male monkeys only? How do we conclude that presence of female monkeys is more important than the presence of unrelated monkeys. The presence of unrelated monkeys is common in 2) and 3).

Could you please clarify?

[jlucero]

2) It still exists but is not quite as bad when monkeys are caged with other unrelated juvenile monkeys and adult males.
3) It still exists but is even less prevalent when monkeys are caged with other unrelated adult male and female monkeys. ("These behaviors are . . . the least prevalent, but still observable, when the monkeys are caged with a mixed-gender group of unrelated, adult monkeys")

Hello Instructors,

The difference between 2) and 3) is the presence of female monkeys.

However, the answer choice B says that the "The presence of unrelated adult female monkeys is more important to juvenile monkeys ****** than is the presence of unrelated juvenile monkeys."

However, this does not sound true. Is it not that the presence of female monkeys is more important than the presence of male monkeys only? How do we conclude that presence of female monkeys is more important than the presence of unrelated monkeys. The presence of unrelated monkeys is common in 2) and 3).

Could you please clarify?

Let me restate Jamie's breakdown at a simpler level. From most to least stressed:

1) monkey alone (scenario 1)
2) monkey + adult males + juveniles (scenario 2)
3) monkey + adult males + adult females (scenario 3)
4) monkey + mother

Note that what's being traded out in scenarios 2 + 3 is juveniles for adult females. Unrelated adult males is common in these two scenarios, but:

(B) The presence of unrelated adult female monkeys is more important to juvenile monkeys in alleviating distress caused by being separated from their mothers (scenarios 3 vs 4) than is the presence of unrelated juvenile monkeys (scenarios 2 vs 3).

or restated in a simpler way:

In alleviating distress caused by being separated from their mothers, the presence of adult females is more important that the presence of unrelated juveniles.

[DanielK746]

I also thought the question could have problematic elements.

First, it doesn't provide isolated incidents of impact of population, and requires incorrect inference, which would not be accepted by any social scientist. Scenarios are:

(0) Separated from mother, self-destructive
(1) Alone, self-destructive
(2) Addition of juvenile and adult male, less self-destructive
(3) Removal of juvenile and addition of adult female, least self-destructive

The correct answer "B", with which I disagree. In true study, the impact of female adult, male adult, and juvenile should be tested in isolation, and then again for differing groups.

For example, it could very well be the case, that the least destructive behavior only occurs when mixed gender adult monkeys are present, not because of female monkeys. To test this hypothesis, scenario (2) should be re-tested with juvenile monkeys and adult female monkeys. If the results are the same as the original (2), the cause of least-destructive behavior is due to having BOTH male and female adult monkeys, not necessarily the presence of female monkeys.

Ignoring interacting variables, and making inferences would never be accepted in any academic setting. From this perspective, answer D almost seems like a better answer:

"Juvenile monkeys that display self-destructive behavior will engage in this behavior the least when reunited with their mothers, and will engage in this behavior slightly more when caged with adult female monkeys who are not their mothers."

The cause of the behavior was separation as noted, and therefore, it is reasonable inference (unlike choice B), to remove the cause will remove the behavior. The second part, has already been proven, then with interaction with other monkeys other than the mother, self-destructive behavior would be worse than being with the mother.

Would love some thoughts on this.

[Sage Pearce-Higgins]

Thanks for posting and sharing your thoughts. It's important to remember that we're doing a GMAT problem here, not writing a science paper. GMAT critical reasoning sticks to the logic of the situation, and doesn't require background knowledge of how we'd design an experiment in a real scientific setting.

I agree with you that the correct answer "requires incorrect inference" and would "not be accepted by any social scientist." However, we're not looking for an inference here. (To be clear, by inference, I mean a statement that can be deduced from other statements with certainty.) The question here is looking for an explanation, not an inference. There may be other explanations for the situation described, and the explanation in the correct answer may not be a perfect one (note that the question asks for the answer that "best explains").

Although GMAT problems don't require a knowledge of scientific method, they do their best to be consistent with good practice of science, and the term 'hypothesis' is significant here. Think what a hypothesis is - I'd describe it as a 'junior theory', the sort of thing that a scientist might say "hey, perhaps this would explain the situation". Scientists often invent new hypotheses that are uncertain, and then they go on to test them in some of the ways you describe. The point is that, for the purposes of this question, we don't need to investigate whether the hypothesis is true, just whether it explains the monkeys' behavior.

With this in mind, answer E sounds like a restatement of some of the information given, but actually goes beyond it. We don't know how these monkeys would behave if they were reunited with their mothers. I'd describe E as a bad inference; it doesn't help us answer the question 'why?'.

Answer D is the most common trap, because it's plausible to think that the unrelated adult female monkeys are some kind of 'substitute' for the juvenile monkeys' mothers. However, the problem phrase here is 'suitable substitute'. If the unrelated female monkeys were suitable substitutes, then we'd expect the juvenile monkeys not to engage in any self-destructive behavior. Answer D leaves us with another puzzle.