2016 GMAT official guide weaken Q

[katrizenis]

124. It is widely assumed that people need to engage in intellectual activities such as solving crossword puzzles or mathematics problems in order to maintain mental sharpness as they age. In fact, however, simply talking to other people-that is, participating in social interaction, which engages many mental and perceptual skills-suffices. Evidence to this effect comes from a study showing that the more social contact people report, the better their mental skills.

Which of the following, if true, most seriously weakens the force of the evidence cited?

(A) As people grow older, they are often advised to keep exercising their physical and mental capacities in order to maintain or improve them.
(B) Many medical conditions and treatments that adversely affect a person's mental sharpness also tend to increase that person's social isolation.
(C) Many people are proficient both in social interactions and in solving mathematical problems.
(D) The study did not itself collect data but analyzed data bearing on the issue from prior studies.
(E) The tasks evaluating mental sharpness for which data were compiled by the study were more akin to mathematics problems than to conversation.

[GMATGuruNY]

124. It is widely assumed that people need to engage in intellectual activities such as solving crossword puzzles or mathematics problems in order to maintain mental sharpness as they age. In fact, however, simply talking to other people-that is, participating in social interaction, which engages many mental and perceptual skills-suffices
. Evidence to this effect comes from a study showing that the more social contact people report, the better their mental skills.

Which of the following, if true, most seriously weakens the force of the evidence cited?

(A) As people grow older, they are often advised to keep exercising their physical and mental capacities in order to maintain or improve them.
(B) Many medical conditions and treatments that adversely affect a person's mental sharpness also tend to increase that person's social isolation.
(C) Many people are proficient both in social interactions and in solving mathematical problems.
(D) The study did not itself collect data but analyzed data bearing on the issue from prior studies.
(E) The tasks evaluating mental sharpness for which data were compiled by the study were more akin to mathematics problems than to conversation.

Premise: The more social contact people report, the better their mental skills.
Conclusion: To maintain mental sharpness...social interaction suffices.

This is a CAUSAL ARGUMENT.
In a causal argument, events A and B are observed together, and the argument concludes that A causes B.
Here, social interaction and mental sharpness are observed together, and the argument concludes that social interaction CAUSES mental sharpness.
Put another way, the argument concludes that a LACK of social interaction causes a LACK of mental sharpness.

One way to weaken a causal relationship is to introduce an ALTERNATE CAUSE.
Answer choice B:
Many medical conditions and treatments that adversely affect a person's mental sharpness also tend to increase that person's social isolation.
Here, a lack of mental sharpness and a lack of social interaction are both caused by MEDICAL CONDITIONS AND TREATMENTS, weakening the conclusion that a lack of social interaction causes a lack of mental sharpness.

The correct answer is B.

[src_saurav]

Mitch, i tried to reject the study here. I chose D as it says that study is based on past collected data.

Please explain.

[GMATGuruNY]

Mitch, i tried to reject the study here. I chose D as it says that study is based on past collected data.

Please explain.

EVIDENCE...comes from A STUDY showing that the more social contact people report, the better their mental skills.
Since the study provides EVIDENCE, the study serves as a PREMISE.
A premise is a FACT; it cannot be weakened.
Eliminate any answer choice that attempts to weaken a premise.
D: The study did not itself collect data but analyzed data bearing on the issue from prior studies.
Since D attempts to weaken the premise offered by the study, eliminate D.

[src_saurav]

Hi Mitch,

Please explain when we can prove a study sample to be inconclusive.

[GMATGuruNY]

Hi Mitch,

Please explain when we can prove a study sample to be inconclusive.

To weaken a SAMPLING CR, the correct answer will typically show that the SAMPLING is not representative of the WHOLE.
Two examples:
https://www.beatthegmat.com/pls-explain-t283596.html
https://www.beatthegmat.com/people-who-h ... 85101.html

[Mo2men]

124. It is widely assumed that people need to engage in intellectual activities such as solving crossword puzzles or mathematics problems in order to maintain mental sharpness as they age. In fact, however, simply talking to other people-that is, participating in social interaction, which engages many mental and perceptual skills-suffices
. Evidence to this effect comes from a study showing that the more social contact people report, the better their mental skills.

Which of the following, if true, most seriously weakens the force of the evidence cited?

(A) As people grow older, they are often advised to keep exercising their physical and mental capacities in order to maintain or improve them.
(B) Many medical conditions and treatments that adversely affect a person's mental sharpness also tend to increase that person's social isolation.
(C) Many people are proficient both in social interactions and in solving mathematical problems.
(D) The study did not itself collect data but analyzed data bearing on the issue from prior studies.
(E) The tasks evaluating mental sharpness for which data were compiled by the study were more akin to mathematics problems than to conversation.

Premise: The more social contact people report, the better their mental skills.
Conclusion: To maintain mental sharpness...social interaction suffices.

This is a CAUSAL ARGUMENT.
In a causal argument, events A and B are observed together, and the argument concludes that A causes B.
Here, social interaction and mental sharpness are observed together, and the argument concludes that social interaction CAUSES mental sharpness.
Put another way, the argument concludes that a LACK of social interaction causes a LACK of mental sharpness.

One way to weaken a causal relationship is to introduce an ALTERNATE CAUSE.
Answer choice B:
Many medical conditions and treatments that adversely affect a person's mental sharpness also tend to increase that person's social isolation.
Here, a lack of mental sharpness and a lack of social interaction are both caused by MEDICAL CONDITIONS AND TREATMENTS, weakening the conclusion that a lack of social interaction causes a lack of mental sharpness.

The correct answer is B.

Hi Mitch,
Although I agree that B is the correct answer, I think it is not an alternate cause. I believe it is introducing a 3rd factor that muddle the relationship between social interaction and mental skills. Answer B is not on the ordinary form of giving direct alternate cause. For example, it does say that spending time with parents affect the mental skills.

What do you think??

[GMATGuruNY]

Hi Mitch,
Although I agree that B is the correct answer, I think it is not an alternate cause. I believe it is introducing a 3rd factor that muddle the relationship between social interaction and mental skills. Answer B is not on the ordinary form of giving direct alternate cause. For example, it does say that spending time with parents affect the mental skills.

What do you think??

B: Many medical conditions and treatments...adversely affect a person's mental sharpness.
Here, a lack of mental sharpness is due not to social isolation but to an ALTERNATE CAUSE: many medical conditions and treatments.

[gmat_for_life]

Hello Mitch,

In one of your explanations provided above, you've written that'Here, social interaction and mental sharpness are observed together, and the argument concludes that social interaction CAUSES mental sharpness.
Put another way, the argument concludes that a LACK of social interaction causes a LACK of mental sharpness. '

My question is that if A causes B, then can we directly negate both sides as in NOT A-> NOT B or should it be NOT B-> NOT A? Which correlation out of the two is being applied in this case?

Regards,
Amit

[GMATGuruNY]

My question is that if A causes B, then can we directly negate both sides as in NOT A-> NOT B or should it be NOT B-> NOT A? Which correlation out of the two is being applied in this case?

Regards,
Amit

Not quite.
A -> B does not imply that Not A -> Not B.

The wording here is unique.
From the passage:
The more social contact people report, the better their mental skills.
This conclusion suggests that the relationship between social contact and mental skills is PROPORTIONATE:
A INCREASE in social contact leads to a proportionate INCREASE in mental skills.
A DECREASE in social contact leads to a proportionate DECREASE in mental skills.

Hence my statement above:
Put another way, the argument concludes that a LACK of social interaction causes a LACK of mental sharpness.

[RBBmba@2014]

EVIDENCE...comes from A STUDY showing that the more social contact people report, the better their mental skills.
Since the study provides EVIDENCE, the study serves as a PREMISE.
A premise is a FACT; it cannot be weakened.
Eliminate any answer choice that attempts to weaken a premise.
D: The study did not itself collect data but analyzed data bearing on the issue from prior studies.
Since D attempts to weaken the premise offered by the study, eliminate D.

Even if D is true, I think, it doesn't affect the CONCLUSION that the more social contact people report, the better their mental skills.
Isn't it ?

A -> B does not imply that Not A -> Not B.

NOT able to understand this!

GENERALLY, in a GMAT STRENGTHEN CR, if we've A caused B or A has led to B or If A then B, then any answer choice that indicates If NOT A then NOT B,should be a potential STRENGTHENER, I guess. (because MUST BE TRUE aspect doesn't hold true in a STRENGTHEN CR)

Am I correct ?

[evs.teja]

124. It is widely assumed that people need to engage in intellectual activities such as solving crossword puzzles or mathematics problems in order to maintain mental sharpness as they age. In fact, however, simply talking to other people-that is, participating in social interaction, which engages many mental and perceptual skills-suffices
. Evidence to this effect comes from a study showing that the more social contact people report, the better their mental skills.

Which of the following, if true, most seriously weakens the force of the evidence cited?

(A) As people grow older, they are often advised to keep exercising their physical and mental capacities in order to maintain or improve them.
(B) Many medical conditions and treatments that adversely affect a person's mental sharpness also tend to increase that person's social isolation.
(C) Many people are proficient both in social interactions and in solving mathematical problems.
(D) The study did not itself collect data but analyzed data bearing on the issue from prior studies.
(E) The tasks evaluating mental sharpness for which data were compiled by the study were more akin to mathematics problems than to conversation.

Premise: The more social contact people report, the better their mental skills.
Conclusion: To maintain mental sharpness...social interaction suffices.

This is a CAUSAL ARGUMENT.
In a causal argument, events A and B are observed together, and the argument concludes that A causes B.
Here, social interaction and mental sharpness are observed together, and the argument concludes that social interaction CAUSES mental sharpness.
Put another way, the argument concludes that a LACK of social interaction causes a LACK of mental sharpness.

One way to weaken a causal relationship is to introduce an ALTERNATE CAUSE.
Answer choice B:
Many medical conditions and treatments that adversely affect a person's mental sharpness also tend to increase that person's social isolation.
Here, a lack of mental sharpness and a lack of social interaction are both caused by MEDICAL CONDITIONS AND TREATMENTS, weakening the conclusion that a lack of social interaction causes a lack of mental sharpness.

The correct answer is B.

Dear Mitch,
I marked option E and am still not clear as to why this is wrong ?
Will appreciate if you clear this doubt , Also
if you throw some light on how to identify and tackle such question.

Agreed that the premise states that social interaction CAUSES mental sharpness,
But if I go with the current correct option, doesn't it state that only social interaction and nothing else CAUSES mental sharpness?
How did you reach there or where am I thinking wrong ?
Please help me out!!

Regards
Teja

[MartyMurray]

EVIDENCE...comes from A STUDY showing that the more social contact people report, the better their mental skills.
Since the study provides EVIDENCE, the study serves as a PREMISE.
A premise is a FACT; it cannot be weakened.
Eliminate any answer choice that attempts to weaken a premise.
D: The study did not itself collect data but analyzed data bearing on the issue from prior studies.
Since D attempts to weaken the premise offered by the study, eliminate D.

Even if D is true, I think, it doesn't affect the CONCLUSION that the more social contact people report, the better their mental skills.
Isn't it ?

That is correct. The fact that the data comes from other studies does not really change anything.

A -> B does not imply that Not A -> Not B.

NOT able to understand this!

GENERALLY, in a GMAT STRENGTHEN CR, if we've A caused B or A has led to B or If A then B, then any answer choice that indicates If NOT A then NOT B,should be a potential STRENGTHENER, I guess. (because MUST BE TRUE aspect doesn't hold true in a STRENGTHEN CR)

Am I correct ?

Mitch's point is simply that A -> B does not IMPLY Not A -> Not B.

In other words, the fact that A causes B cannot be used to conclude that if A is not the case then B is not the case.

B could be caused by things other than A.

If you drink too much you will get sick does not imply that if you do not drink too much you will never get sick.

[RBBmba@2014]

Mitch's point is simply that A -> B does not IMPLY Not A -> Not B.

In other words, the fact that A causes B cannot be used to conclude that if A is not the case then B is not the case.

B could be caused by things other than A.

If you drink too much you will get sick does not imply that if you do not drink too much you will never get sick.

Hi,
Can you please let me know whether my following understanding is correct for STRENGTHEN CR ?

GENERALLY, in a GMAT STRENGTHEN CR, if we've A caused B or A has led to B or If A then B, then any answer choice that indicates If NOT A then NOT B,should be a potential STRENGTHENER, I guess. (because MUST BE TRUE aspect doesn't hold true in a STRENGTHEN CR)

Thoughts please!

[RBBmba@2014]

Marty - any update on the above Sir ?

Curious to know your thoughts!