Reading Comprehension

Social learning in animals
is said to occur when direct
or indirect social interaction
Line facilitates the acquisition
(5) of a novel behavior. It
usually takes the form of
an experienced animal (the
demonstrator) performing a
behavior such that the naive
(10) animal (the observer) subsequently
expresses the
same behavior sooner, or
more completely, than it
would have otherwise. One
(15) example of social learning
is the acquisition of preferences
for novel foods.
Some experiments
have suggested that among
(20) mammals, social learning
facilitates the identification
of beneficial food items,
but that among birds, social
learning helps animals
(25) avoid toxic substances.
For example, one study
showed that when red-wing
blackbirds observed others
consuming a colored food
(30) or a food in a distinctly
marked container and then
becoming ill, they subsequently
avoided food
associated with that color
(35) or container. Another
experiment showed that
house sparrows consumed
less red food after they
observed others eating
(40) red food that was treated
so as to be noxious. Studies
on nonavian species have
not produced similar results,
leading researchers to
(45) speculate that avian social
learning may be fundamentally
different from that of
mammals.
But Sherwin's recent
(50) experiments with domestic
hens do not support the
notion that avian social
learning necessarily facilitates
aversion to novel
(55) foods that are noxious or
toxic. Even when demonstrator
hens reacted with
obvious disgust to a specific
food, via vigorous head
(60) shaking and bill wiping,
there was no evidence that
observers subsequently
avoided eating that food.
Sherwin's research team
(65) speculated that ecological
or social constraints during
the evolution of this species
might have resulted in there
being little benefit from the
(70) social learning of unpalatability,
for instance,
selective pressures for this
mode of learning would be
reduced if the birds rarely
(75) encountered noxious or
toxic food or rarely interacted
after eating such food,
or if the consequences of
ingestion were minimal.

The primary purpose of the passage is to discuss the
A. techniques used in certain experiments on social learning in birds
B. reasons for the differences between social learning in birds and in mammals
C. question of how social learning manifests itself in birds
D. basis for a widespread belief about a difference in behavior between birds and
mammals
E. possible reasons why birds may or may not learn from each other in a particular
way

OA:E

I was torn between C and E. Can anybody explain why C is wrong. If it's E, then doesn't it ignore the first half of the passage?

A. Techniques / experiments are only examples and do not represent the primary purpose.

B. No specific reasons for the differences between birds and mammals are cited. Only the difference itself is noted.

C. How does it manifest? The only mention of this is in the speculation at the end of the passage where the author mentions constraints and pressures for such learning. However this is not really the main purpose, which seems to be more about circumstances in which birds learn from eachother.

D. Too broad. No real widespread belief here.

E. This addresses the question being attended to in most of the paragraph. You are right, the introductory paragrapher is broader but if you notice, it leads into the main point of the passage, and hence need not be included in the purpose. More importantly. between C and E. E is actually the more holistic view of the passage, and though as you said it may not encompass it entirely, it is the best choice and that is all that matters on the GMAT. C is too specific towards the speculations at the end of the passage.

Pick E.

albatross86 wrote:A. Techniques / experiments are only examples and do not represent the primary purpose.

B. No specific reasons for the differences between birds and mammals are cited. Only the difference itself is noted.

C. How does it manifest? The only mention of this is in the speculation at the end of the passage where the author mentions constraints and pressures for such learning. However this is not really the main purpose, which seems to be more about circumstances in which birds learn from eachother.

D. Too broad. No real widespread belief here.

E. This addresses the question being attended to in most of the paragraph. You are right, the introductory paragrapher is broader but if you notice, it leads into the main point of the passage, and hence need not be included in the purpose. More importantly. between C and E. E is actually the more holistic view of the passage, and though as you said it may not encompass it entirely, it is the best choice and that is all that matters on the GMAT. C is too specific towards the speculations at the end of the passage.

Pick E.

IMHO- E encapsulates the complete theme and highlights the primary purpose-

Ist part says Social learning happens but in different mode between Birds and Mammal's.

IInd Part say's, well that may not be entirely true-as in Domestic Hen social learning does not happens.

Author further goes on to say that "Sherwin’s research team speculated that ecological or social constraints during the evolution of this species might have resulted in there being little benefit from the social learning of unpalatability" - and thus we can say primary purpose is :"possible reasons why birds May or May Not learn from each other in a particular way.

Thanks for the explanations. I can see now why E is the better choice and why it captures the purpose of the passage.

I had marked C, the going is getting tough!

Why is B wrong though...I don't see why E is right..

Another question in the same RC that is bothering me.

According to the passage, which of the following is true of the experiments on domestic hens conducted by Sherwin's research team?

A. Only a small number of observer hens appeared to learn to avoid food that was demonstrated by other hens to be noxious.
B. Observer hens ingested food preferentially only after numerous instances of witnessing demonstrator hens preferentially ingest that type of food.
C. Observer hens appeared unable to recognize when demonstrator hens found a particular food especially palatable.
D. Demonstrator hens reacted adversely to ingesting certain novel foods.
E. Demonstrator hens altered their behavior less obviously in response to noxious foods than in response to highly palatable foods.

Could someone please explain the answer ? OA after discussion.

prepgmat09 wrote:Another question in the same RC that is bothering me.

According to the passage, which of the following is true of the experiments on domestic hens conducted by Sherwin's research team?

A. Only a small number of observer hens appeared to learn to avoid food that was demonstrated by other hens to be noxious.
B. Observer hens ingested food preferentially only after numerous instances of witnessing demonstrator hens preferentially ingest that type of food.
C. Observer hens appeared unable to recognize when demonstrator hens found a particular food especially palatable.
D. Demonstrator hens reacted adversely to ingesting certain novel foods.
E. Demonstrator hens altered their behavior less obviously in response to noxious foods than in response to highly palatable foods.

Could someone please explain the answer ? OA after discussion.

The answer hinges on these lines... it depends on how we understand it...

Even when demonstrator
hens reacted with
obvious disgust to a specific
food, via vigorous head
(60) shaking and bill wiping,
there was no evidence that
observers subsequently
avoided eating that food.

A seems tempting... but is wrong as there is no indication of even 1 hen that avoided eating noxious food.
B is not mentioned
C...lets park it for now...
D is exactly the opposite...
E seems better than C,
in C lets hypothesize..that indeed the hen were able to understand the demonstrator's behavior, but did not heed to the noxious indications because they knew the demonstrator could be decieving them.
E takes a concilliatory step...and says that as a general practice hens usually did not change their behavior to noxious food instead changed their behavior when the food was tasty, so the observer hen took it as a signal to savor the food rather than avoid it by deeming it noxious.

arora007 wrote:
The answer hinges on these lines... it depends on how we understand it...

Even when demonstrator
hens reacted with
obvious disgust to a specific
food, via vigorous head
(60) shaking and bill wiping,
there was no evidence that
observers subsequently
avoided eating that food.

A seems tempting... but is wrong as there is no indication of even 1 hen that avoided eating noxious food.
B is not mentioned
C...lets park it for now...
D is exactly the opposite...
E seems better than C,
in C lets hypothesize..that indeed the hen were able to understand the demonstrator's behavior, but did not heed to the noxious indications because they knew the demonstrator could be decieving them.
E takes a concilliatory step...and says that as a general practice hens usually did not change their behavior to noxious food instead changed their behavior when the food was tasty, so the observer hen took it as a signal to savor the food rather than avoid it by deeming it noxious.

Hi Arora,

Thanks for responding.

However, I am still not quite convinced. Where/How does the passage compare hens' behavior towards noxious food to its behaviour towards pallatable food? The lines you quoted just mention that observer hens seem to be indifferent to demontrator hens's apparent disgust towards some specific food.

prepgmat09 wrote: hens seem to be indifferent to demonstrator hens's apparent disgust towards some specific food.

Thanked u when i needed to quote.. aneways...

well...thats what many of us infer(that the hens were indifferent) from the author's statement...

Even when demonstrator
hens reacted with
obvious disgust to a specific
food, via vigorous head
(60) shaking and bill wiping,
there was no evidence that
observers subsequently
avoided eating that food.

The shaking of the head by the demonstrator... did not result in observers avoiding to eat food.

It could have been two reasons...
1/ the observers were indifferent
or
2/ the observers were convinced that the demonstrators savoured the food and acknowledged it by shaking their head.

No choice leads us to the answer as close as E.

what is ur take?which choice?

To be honest, I think either I am not getting the point you are trying to emphasize or we are not on the same page.

How can observers be convinced that demonstrators savoured the food when "demonstrator hens reacted with obvious disgust" ? And what has this got to do with comparison between demostrator hens' behavior towards noxious food and their behaviour towards pallatable food?

I am completely lost

prepgmat09 wrote:To be honest, I think either I am not getting the point you are trying to emphasize or we are not on the same page.

How can observers be convinced that demonstrators savoured the food when "demonstrator hens reacted with obvious disgust" ? And what has this got to do with comparison between demostrator hens' behavior towards noxious food and their behaviour towards pallatable food?

I am completely lost

Its our interpretation that shaking the head it out of disgust... it could be that observers took it as a positive signal...E supports this thinking!

prepgmat09 wrote:Another question in the same RC that is bothering me.

According to the passage, which of the following is true of the experiments on domestic hens conducted by Sherwin's research team?

A. Only a small number of observer hens appeared to learn to avoid food that was demonstrated by other hens to be noxious.
B. Observer hens ingested food preferentially only after numerous instances of witnessing demonstrator hens preferentially ingest that type of food.
C. Observer hens appeared unable to recognize when demonstrator hens found a particular food especially palatable.
D. Demonstrator hens reacted adversely to ingesting certain novel foods.
E. Demonstrator hens altered their behavior less obviously in response to noxious foods than in response to highly palatable foods.

Could someone please explain the answer ? OA after discussion.

This is a must be true type question:

IMO D

Well for me the organization of the passage gives the answer.

It has been mentioned in the beginning of the passage that mammals and birds have differences in social learning but it has not been mentioned again. And the passage mainly discuss the examples of birds not of comparisons between mammals and birds, therefore B is not the answer.

The passage hardly focuses on the techniques used in the experiments. So A is not the answer.

Manifestation is changes or adaptations of a certain phenomenon there are no adaptations given in the passage. C is not the answer.

Reason for rejecting D are the same as B

Now for E: First two examples give the way red wings and sparrows interpret the same things in similar ways and hens don't interpret anything from similar phenomenon and the reasons have been provided in the last line of the passage.
Therefore E is the Answer

E: Reasons narrow down the scope of the passage by talking about one aspect of the theme

While C clearly mentions the broad theme of the passage, which talks about how social learning is evident among birds (manifest=birds)