A team of researchers from MIT studied the effects of

Question

The following question is based on an article in Scientific American:

A team of researchers from the Massachusetts Institute of Technology studied the effects of yogurt on mating. The researchers took a group of 40 male mice and 40 female mice and either fed the animals a high-fat, low-fiber, low-nutrient diet meant to mimic junk food or fed them standard mouse meals. They then supplemented half of each diet group with vanilla-flavored yogurt.In mating experiments, yogurt-eating males inseminated their partners faster and produced more offspring than control mice. Conversely, females that ate the yogurt diets gave birth to larger litters and weaned those pups with greater success. The researchers concluded that the probiotic microbes in the yogurt help to make the animals leaner and healthier, which indirectly improves sexual machismo.

Which of the following if true, would most weaken the conclusion reached by the researchers?

A.Many of the mice in the control group died soon after the experiment
B.In another study, probiotic microbes were not found to produce any significant health benefits
C.Yogurt is not the only food which contains a high concentration of probiotic microbes
D.Mating advantage of the yogurt eating mice reduced in a few days after they stopped taking yogurt
E.The female yogurt eating mice were healthier than their male counterparts

m3equals333 · Accepted Answer

A: Opens up the possibility that the yogurt eating mice did not actually have enhanced mating capabilities, but rather that the non yogurt eating mice (control) had diminished mating capabilities

another reason B may not be the credited answer is because it fails to address the probiotic microbes --> improved physique --> improved mating aspect of the argument. There is no rule that a physically fit/lean individual has to be in good health (and, conversely, that an overweight individual has to be in poor health)....jmo

A is definitely not perfect either, but seems to directly attack the final conclusion, whereas B seems to attack the (intermediary?) conclusion as a device to get at the final conclusion

Marcab · Answer

The answer lies in the last statement of the stimulus. . 
To weaken the conclusion, if we are able to produce any negative effect which helps in the deterioration of the health of the mice, then we can find the required answer. 
Only a provides that there is some negative effect of probiotic microbes in yogurt.
Hence straight A.

Practicegmat · Answer

I marked (B)
Can anyone explain why the correct answer is not B ?

"In another study, probiotic microbes were not found to produce any significant health benefits"

This option weakens the chance that the mice became leaner and healthier because of the yogart, but may be for something else.

SVaidyaraman · Answer

Dear Practicegmat,

We do not know anything about the other study. It might have been flawed. So without knowing anything more than its conclusion , we cannot use it to weaken the conclusion of this study.

hariprasad · Answer

Hai,

Could you clarify my doubt??

''In mating experiments, yogurt-eating males inseminated their partners faster and produced more offspring than control mice.''

From the previous quote, I understood that the ''control mice'' are the ones that were not fed with yogurt. As stated in option A, How yogurt had a negative effect on them, ?? Pl clarify.

Thanks.

SVaidyaraman · Answer

Hi,

The negative effect was not in the yogurt but in the meal provided to the control mice

khosru · Answer

in the stimulus it is stated that "yogurt-eating males inseminated their partners faster and produced more offspring than control mice" so it is clear that control group didn't eat yogurt. so it is completely irrelevant if they die as stated in A. The answer is B.

Skywalker18 · Answer

Yogurt - eating males became more sexually active - inseminated faster and produced more offspring
Yogurt - eating females gave birth to more little mice

Conclusion - Probiotic microbes in yogurt --> make animals healthier and leaner, which indirectly improves sexual machismo

B. We are not aware of the conditions and factors in the other study. Out of scope
C. Just because some other food might also contain high concentration of probiotic microbes doesn't make yougurt bad.
D.If anything this is a mild strengthener as it reconfirms that yougurt caused the mating advantage.
E.Male v/s female health doesn't weaken that yogurt causes good health.

A. It seems to suggest that mating advantage might not be indicative of good health . Weakens

Answer A

Nevernevergiveup · Answer

A team of researchers from the Massachusetts Institute of Technology studied the effects of yogurt on mating. The researchers took a group of 40 male mice and 40 female mice and either fed the animals a high-fat, low-fiber, low-nutrient diet meant to mimic junk food or fed them standard mouse meals. They then supplemented half of each diet group with vanilla-flavored yogurt.In mating experiments, yogurt-eating males inseminated their partners faster and produced more offspring than control mice. Conversely, females that ate the yogurt diets gave birth to larger litters and weaned those pups with greater success. The researchers concluded that the probiotic microbes in the yogurt help to make the animals leaner and healthier, which indirectly improves sexual machismo.

Which of the following if true, would most weaken the conclusion reached by the researchers?

A. Many of the mice in the control group died soon after the experiment.
 You cannot say they are healthier and they died. May be they are healthier as expected thereby weakening the conclusion.

B. In another study, probiotic microbes were not found to produce any significant health benefits.
 (We are not sure whether the remaining aspects of that study or conditions of experiment are similar or not. Moreover not much significant does not mean there are no health benefits. It just says not much.)

C. Yogurt is not the only food which contains a high concentration of probiotic microbes.
 (they did not say yogurt is the only food which contains probiotic microbes. they just said it contains them. not relevant )

D. Mating advantage of the yogurt eating mice reduced in a few days after they stopped taking yogurt.
 (This supports the conclusion saying yogurt improves sexual machismo.)

E. The female yogurt eating mice were healthier than their male counterparts.
 (The conclusion regarding both sections of mice and yogurt. This comparison is irrelevant.)

goforgmat · Answer

im not convinced with the OA..
My reasoning as below

group fed with junk food:20/40 were fed ypgurt
group fed with normal mice diet:20/40 were fed with yogurt
according to premise :"They then supplemented half of each diet group with vanilla-flavored yogurt."

thr answer choice says Many which can be equated to 51%-100%

how do we now for sure in this that the mice that died had infact been fed with y0gurt .it could include the control gourp not fed with yogurt as well.
Experts let me know where i am going wrong

pkm9995 · Answer

A. Many of the mice in the control group died soon after the experiment.

But control group = all mice under study. So dead mice can be those ,which had or never had yogurt. This can only weaken if the dead mice were from the group which consumed yogurt. Confused

dayasantoshi · Answer

I do not agree with the OA. Please find below my reasoning. Can anyone help?  VeritasPrepKarishma ,  bb  , egmat ,  mikemcgarry ,  ChrisLele

A control group in any experiment is a group of subjects that closely resemble the experimental group but do not receive the experiment drug ( in this case- yogurt). A control group serves as a reference to compare with the experimental group.

Experiment group - Yogurt mice, 
Control group - Mice who are not given yogurt.

A. Many of the mice in the control group died soon after the experiment.  If the mice in the control group dies, it means yogurt is required for survival. If anything, it strengthens the conclusion

B. In another study, probiotic microbes were not found to produce any significant health benefits. -  Conclusion talks about probiotic microbes in yogurt

C. Yogurt is not the only food which contains a high concentration of probiotic microbes. -  Though not a strong weakening point, this implies that the results are based on 2 diets, junk and mouse meals and maybe probiotic microbes in these food could have been the contributor and not the probiotic microbes in the yogurt as the conclusion states.
 
D. Mating advantage of the yogurt eating mice reduced in a few days after they stopped taking yogurt. -  Irrelevant

E. The female yogurt eating mice were healthier than their male counterparts. - Irrelevant

Anonamy · Answer

Don't agree with the OA provided either as A does not specify which control group it refers to... Awaiting clarity.

AryamaDuttaSaikia · Answer

The correct answer should be "C". The conclusion states it is not Yogurt but the probiotic microbes in Yogurt which make these mice leaner and healthier. If the other mouse meals contained probiotic microbes that could be the reason for leaner and healthier mice. Hence "C" seems to suggest that. In "A" control group suggests these mice were not a part of the experiment. Hence they were not fed Yogurt. So their death does not prove anything.

sandman13 · Answer

Can you please walk us through all the options? I'm not entirely convinced how A weakens. I chose B.

Gagoosh · Answer

I am no expert of CR, but let me attempt to explain this one.

A study was conducted, in which a batch of 40 mice was divided into yoghurt eating group and a control group(no yoghurt eating). Yoghurt eating participants fared better than their counterparts. Conclusion drawn : yoghurt (probiotics) is the cause for healthier and leaner mice(effect). Assumption : No other factor triggering the effect.

To weaken this assumption, we would bring in a factor that effectively explains the result of the study. Choice A says many mice from the control group died. If 50% of mice showed the sexual machismo, it would mean 5/10 mice from yoghurt eating group fared well. Whereas if say 2 mice died in the control group, out of 8 mice, 50% showed sexual machismo, it would still bring in a result of 4/10. Despite the same ratio of 50%, Yoghurt eating batch gives a better result. Hence A weakens.

Please kudos if that helped.

SonGoku · Answer

Let me try
 shelleyjohnsam  
 CONCLUSION :  the probiotic microbes in the yogurt help to make the animals leaner and healthier, which indirectly improves sexual machismo.

We need to weaken the above conclusion .

If many of the mice in the control group died after the experiment means how can we know that the probotic mcrobes in the yogurt help make the animals leaner and healthier, and how can we know that it improves sexual machismo without observing it for a while. so if they are dead the conclusion is weakened.keep it.
 
we need to find the reasons to weaken it not to contradict the argument and we are talking about this study not other studies and its more like an evidence rather than a weakener.eliminate it.
 
Irrelevant and not mentioned in the passage. eliminate it .
 
strengthener. eliminate it
 
Irrelevant.eliminate it.

If are a conservative then you can eliminate 3 at first and then you can choose between the last two( A and B).
A is the winner here. 
Thank you.

SVaidyaraman · Answer

Let me answer the question.

The mice that were fed yogurt were leaner and healthier than the control mice after the experiment. It is a relative thing. As mentioned in choice A if many mice in the control group died soon after the experiment then it is very likely that the meal provided to the control mice had a negative effect on them. So the result of the experiment could be construed like this: negative effect of the meal fed to the control mice made it look like yogurt having a positive effect on the experimental group.

AdityaHongunti · Answer

A team of researchers from the Massachusetts Institute of Technology studied the effects of yogurt on mating. The researchers took a group of 40 male mice and 40 female mice and either fed the animals a high-fat, low-fiber, low-nutrient diet meant to mimic junk food or fed them standard mouse meals. They then supplemented half of each diet group with vanilla-flavored yogurt.In mating experiments, yogurt-eating males inseminated their partners faster and produced more offspring than control mice. Conversely, females that ate the yogurt diets gave birth to larger litters and weaned those pups with greater success. The researchers concluded that the probiotic microbes in the yogurt help to make the animals leaner and healthier, which indirectly improves sexual machismo.

Which of the following if true, would most weaken the conclusion reached by the researchers?

understanding the argument :
-group A was fed junk food
-group B was fed mouse meal
-half of A was given yogurt and half was not
-half of B was given yogurt and half was not
result : mice with yogurt faster sex than mice without yogurt

conclusion : pro biotic in yogurt >> lean body and healthy>> increases sex drive

NOTE: this is a TYPICAL GMAT comparison study question. Most of the time when we have to weaken the conlusion try to attack the control group because that is the least explicitly mentioned and that is where the argument tries to exploit.
Apply 2 part analysis : whenever we are explicitly provided with results of one group , attack the non explicit group.

Think: we are told that HALF of both A and B were given yogurt and the half were sex crazy. What are we comparing these groups to?? the non yogurt groups ... if the non yogurt group due to some reason (we dont care about the reason...they may as well be inherently weak) was weak and had low sex drive then comapratively the yogurt mice will be better right?? in this case with or without the yogurt the half group(not the control group) will still be more sex crazy..can we conclude that yogurt had some magic?? NOPE

This was my thinking...

A. Many of the mice in the control group died soon after the experiment.
-  SravnaTestPrep  The answer choice could be a little more clear and not confusing. I am not saying that this choice is wrong 100% but it could be worded better and more in line with the student's reasoning. This choice is very ambiguous
reasons:
-many does not mean 50% it could 10% too
- othersin the control group may still be healthy and hence lending strength to the onclusion by making comaprisn valid
- I agree that we do not have to destroy the conclusion outright but still there should atleast be some strong point.
"many "is more like "Some" , it could be "some" (in which case i wouldnt choose this answer) 
- if the asn choice used "most" or "more than half" then this choice would be a more appealing choice
-if we try to be conservative and firm on our belief(which students often tend to be) ,they might make a point for options B and C becasue both of these options are close enough to A.
-each of the three choice A B and C have their own assumptions and each can be valid answer IF tried to prove as even some of the great experts seem to second this view

P.S. plesae do not get offended .I am not being condescending. Just a student trying to make a suggestion to an expert. Please do share your views on this. Thankyou

A team of researchers from MIT studied the effects of

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