12 Days of Christmas GMAT Competition - Day 4: In a certain experiment

Question

12 Days of Christmas GMAT Competition with Lots of Fun

In a certain experiment, participants were placed into one of two groups: Interviewers or Respondents. Each Interviewer was given a standard list of questions to address to one Respondent, while observing the body language of that Respondent. Respondents were privately told either to lie in every response or to tell the truth in every response. Although each Interviewer reported that such indicators as shifting posture, level of eye contact, and hesitation before speaking allowed them to confidently predict who was or was not lying, the overall accuracy of the Interviewer’s predictions was little better than random guessing. The researchers concluded that body language is not an accurate gauge of perceived truthfulness in everyday conversation.

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

(A) Many people become more attentive to others’ body language when specifically instructed to observe it.
(B) People who are intentionally lying often maintain continuous eye contact with the person to whom they are speaking.
(C) In everyday conversation, practically no one always lies or always tells the truth.
(D) None of the participants in the experiment were acquainted with each other before commencement of the experiment.
(E) The questions used in the experiment were innocuous questions with no relevance to an individual’s personal beliefs.

Bunuel · Accepted Answer

Manhattan Prep Official Explanation

Step 1: Identify the Question 
 
The word  weaken  in the question stem indicates that this is a Weaken question.

Step 2: Deconstruct the Argument 
 
In this argument, the conclusion is stated at the end of the paragraph:  Body language is not an accurate gauge of perceived truthfulness in everyday conversation . Although the Interviewers claimed to be able to predict which Respondents were lying based on their body language, their predictions were  little better than random guessing —that is, not accurate.

Step 3: Pause and State the Goal

What assumptions are the researchers making? The researchers conducted this experiment in a way that introduces at least two concerns. First, there is no stated attempt to create a control group in the experiment. A better version of the experiment could have included a group of Interviewers and Respondents who were given no special directions on how to reply to the questions. Second, the researchers draw a conclusion about  everyday life  from one experiment conducted with conditions that differ substantially from real-life situations.

Another possible concern may be the participants themselves. There is no mention of whether the Interviewers have received even cursory instructions of  how  body language might indicate whether a person is lying. What if body language is a reliable indicator of lying, but only when evaluated by a trained eye?

Step 4: Work From Wrong to Right

(A) This answer choice suggests that the Interviewers may have been more attuned to the body language of the Respondents. However, if anything, this answer choice would suggest that the Interviewers’ predictions should have been more accurate. Since the predictions were not accurate, despite expectations, this answer choice actually strengthens the argument.

(B) People who are lying maintain continuous eye contact; what about people who are telling the truth? Even if one assumes that liars intentionally maintain eye contact and truth-tellers do not, that interpretation would strengthen the argument by reinforcing the expectation that body language would be an effective tool to determine whether a person was lying.

(C) CORRECT.  This answer choice may seem irrelevant. Of course people in real life do not normally speak the truth or lie 100% of the time! But if people do not adhere to the strict roles of the experiment in real life, then the results of this experiment cannot be convincingly extrapolated to real-life. In other words, the experiment was too artificial to serve as an everyday life substitute, so the author’s conclusion is weakened.

(D) If anything, this answer choice would strengthen the argument, because it removes one potential variable from the experiment. If some of the participants were previously acquainted before the experiment, then some of the participants might have non-body language related clues to tell when someone was lying or telling the truth.

(E) If anything, this choice would strengthen the argument, because it removes one potential variable from the experiment. For example, what if the questions touched on very personal beliefs held by participants? The emotional impact of the question itself might somehow distort a Respondent’s behavior and make body language a less useful clue to whether that Respondent was lying. This answer choice removes that possible concern and would actually increase the expectation that body language would be a reliable indicator of whether a person is lying. Since body language was not a reliable indicator in this experiment, the researchers’ conclusion would be more convincing.

singhaz · Answer

In a certain experiment, participants were placed into one of two groups: Interviewers or Respondents. Each Interviewer was given a standard list of questions to address to one Respondent, while observing the body language of that Respondent. Respondents were privately told either to lie in every response or to tell the truth in every response. Although each Interviewer reported that such indicators as shifting posture, level of eye contact, and hesitation before speaking allowed them to confidently predict who was or was not lying, the overall accuracy of the Interviewer’s predictions was little better than random guessing. The researchers concluded that  body language is not an accurate gauge of perceived truthfulness in  everyday conversation .

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

(A) Many people become more attentive to others’ body language when specifically instructed to observe it.
(B) People who are intentionally lying often maintain continuous eye contact with the person to whom they are speaking.
(C) In everyday conversation, practically no one always lies or always tells the truth.
 (D) None of the participants in the experiment were acquainted with each other before commencement of the experiment.
If none of the participants know each other then researcher conclusion is not accurate. 
(E) The questions used in the experiment were innocuous questions with no relevance to an individual’s personal beliefs.

Elite097 · Answer

Which of the following, if true, would most weaken the researchers’ conclusion? We are looking for an answer that tells us that body language is an accurate gauge of perceived truthfulness in everyday life. The passage makes a generalization about everyday life based on results of an experiment.

(A) Many people become more attentive to others’ body language when specifically instructed to observe it.----Even if this is so we don't know whether body language is accurate. How people behave in certain circumstances does not matter'

(B) People who are intentionally lying often maintain continuous eye contact with the person to whom they are speaking. -- Ok but we do not know what ppl intentionally telling the truth do. What if they also make continuous eye contact? Then how can we say that body language is an accurate indicator?

(C) In everyday conversation, practically no one always lies or always tells the truth.--- This weakens the conclusion by saying that the generalization does not hold as the situation applicable in the experiment is not the same as the situation in everyday life.

(D) None of the participants in the experiment were acquainted with each other before commencement of the experiment.--We don't know how aquaintance relates to making a judgement
(E) The questions used in the experiment were innocuous questions with no relevance to an individual’s personal beliefs.---We dont know how the situation would differ in case personal beliefs did hold

Ans C

sivatx2 · Answer

Conclusion: Body language is not an accurate gauge of perceived truthfulness in everyday conversation.

In order to weaken the conclusion, there are 2 ways:

1. The proof that body language is accurate gauge of perceived truthfulness.
2. The way conclusion arrived at, is not correct. For example, the entire study/experiment based on which the conclusion was arrived is not covering the scenarios that can prove that body language is not an accurate gauge. It could be that experiment foundation is inaccurate. What if the respondents cannot concretely answer some or all the questions in one way(either all truthful or all lie)? This will invalidate the experiment and hence the result of the experiment. That means, the conclusion is also not valid.

Let's review the options now.

(A) Many people become more attentive to others’ body language when specifically instructed to observe it.
 If the theory that observing body language can lead to find out whether the respondents are speaking truth or lying then this option indirectly strengthens the conclusion, as observing body language is same as randomly guessing. Eliminate.

(B) People who are intentionally lying often maintain continuous eye contact with the person to whom they are speaking.
 This option does not speak about whether respondents who are speaking the truth won't make continuous eye contact, to make this a valid support to either strengthen or weaken the conclusion. Eliminate.

(C) In everyday conversation, practically no one always lies or always tells the truth.
 This option clearly invalidates the experiment. If no one always lies or always tells truth, then the results/conclusion is invalid. Hence this option weakens the conclusion. Keep option C.

(D) None of the participants in the experiment were acquainted with each other before commencement of the experiment.
 Acquaintance is out of scope of the argument as there is no relevancy to perceived truthfulness in everyday conversation. Eliminate

(E) The questions used in the experiment were innocuous questions with no relevance to an individual’s personal beliefs.
 Personal belief is out of scope of the argument as there is no relevancy to perceived truthfulness in everyday conversation. Eliminate

Hence, the best answer choice is C.

UtkarshAnand · Answer

Explanation:
The question asks us to weaken the researcher's conclusion that "body language is not an accurate gauge of perceived truthfulness in everyday conversation".
This can be done by either of the 2 strategies:
Strategy 1: Showing that body language is indeed an accurate gauge of perceived truthfulness in everyday conversation 
or 
Strategy 2: By showing that some other reason (and not body language as an inaccurate gauge of perceived truthfulness in everyday conversation) led to the low accuracy of the interviewer’s predictions.

Now evaluating options:

(A) Many people become more attentive to others’ body language when specifically instructed to observe it.
This rather strengthens the conclusion. When people pay more attention to others' body language, the accuracy should go up rather than going down as the situation presents and hence strengthens the researcher's conclusion citing body language as the culprit. OUT.

(B) People who are intentionally lying often maintain continuous eye contact with the person to whom they are speaking.
The passage just talks about the level of eye contact. It doesn't give further details whether a prolonged or a curtailed eye contact aids in gauging one's body language. So this has no impact on the argument. OUT.

(C) In everyday conversation, practically no one always lies or always tells the truth.
The respondents were privately told either to lie in every response or to tell the truth in every response. The option stating "In everyday conversation, practically no one always lies or always tells the truth" questions/weakens the conclusion as when someone lies in every response or tells the truth in every response, the conversation becomes unnatural making it difficult to gauge the truthfulness of the situation. This gives a credible alternate reason for the low accuracy of interviewer's predictions on the lines of strategy 2. KEEP IT.

(D) None of the participants in the experiment were acquainted with each other before commencement of the experiment.
This rather strengthens the conclusion. If the participants were not acquainted then they had no clue about the respondents' truthfulness and body language would have been the sole indicator for gauging the truthfulness of respondents. The low accuracy as given in the situation directly puts the blame on body language. OUT.

(E) The questions used in the experiment were innocuous questions with no relevance to an individual’s personal beliefs.
This has no relevance with the conclusion of the researchers blaming body language for the low accuracy of interviewer's prediction. OUT.

ANSWER C.

Lizaza · Answer

The message of the prompt is such that because the Interviewers were unable to identify lying based on the body language, body language (BL) in general is a bad telltale sign of truthfulness.

How can we weaken that? Well, to try to disprove the conclusion from any of the angles - that is, try to ascertain the validity of BL:
 - Did the research imitate the real-life conditions well - such as the 'everyday conversation' they mention in conclusion?
- Was there any bias or subjectivity among Interviewers and Respondents?
- Were the Interviewers adequately instructed on what constitutes body language and how to evaluate it? 
And some other possible options - in any case, the statement must really shatter the conclusion, or at least diminish its authority.

Well, let's deal with the options:
 
This is a good contender. Indeed, if the Interviewers were even more attentive than an average Joe, and they still failed to read the BL well - 
doesn't it mean that the whole concept is futile? However, I don't believe that 'many people' is a fully comprehensive metris.
After all, there's always a chance that our Interviewers were not some of the 'many', which makes the whole statement irrelevant. So,   A is wrong.

This is interesting, as it supposes the Respondents may have been misleading.
However, eye contact is only one of the BL aspects, so this is not a comprehensive argument.   B is wrong.

This one delivers the most serious blow to the whole conclusion, because it states there is a significant methodological flaw in the whole experiment.
If the experimental conditions in the first place were designed unlike those of 'everyday conversation', then how can the researchers extrapolate their findings in such a way
and claim that they are applicable in everyday life? Seems like  C is our answer , but let's still read the remaining prompts.

This slightly decreases the biasedness concern - but it does nothing bad for the conclusion, 
because it actually imitates some of the everyday conversation potential aspects, when two strangers meet for the first time.   D is wrong.

Regardless of the type of questions, it should have been possible to identify one's lies - that is to say, in everyday conversation we share any types of information,
so if BL works, it should work regardless of the context (at least as far as the conclusion goes). Therefore,   E is wrong.

Indeed, having considered everything,   С is the right answer.

VerbalBot · Answer

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12 Days of Christmas GMAT Competition - Day 4: In a certain experiment

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