In 1960's studies of rats, scientists found that crowding increases the number of attacks among the animals significantly. But in...
GMAT Critical Reasoning : (CR) Questions
In 1960's studies of rats, scientists found that crowding increases the number of attacks among the animals significantly. But in recent experiments in which rhesus monkeys were placed in crowded conditions, it was not such attacks that increased significantly, but rather instances of "coping" behavior, such as submissive gestures, avoidance of dominant individuals, and huddling with relatives. Therefore the evidence from rhesus monkeys makes it doubtful that crowding significantly increases aggressive impulses in primates.
Which of the following, if true, most seriously weakens the argument?
Passage Analysis:
| Text from Passage | Analysis |
| In 1960's studies of rats, scientists found that crowding increases the number of attacks among the animals significantly. |
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| But in recent experiments in which rhesus monkeys were placed in crowded conditions, it was not such attacks that increased significantly, but rather instances of "coping" behavior, such as submissive gestures, avoidance of dominant individuals, and huddling with relatives. |
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| Therefore the evidence from rhesus monkeys makes it doubtful that crowding significantly increases aggressive impulses in primates. |
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Argument Flow:
The argument starts with rat studies showing crowding leads to more attacks, then presents monkey studies showing crowding leads to peaceful coping behaviors instead of attacks, and concludes that this monkey evidence challenges the idea that crowding makes primates aggressive.
Main Conclusion:
The evidence from rhesus monkeys makes it doubtful that crowding significantly increases aggressive impulses in primates.
Logical Structure:
The author uses the monkey study results as counter-evidence to challenge a general principle about crowding and aggression in primates. The logic assumes that if one primate species (monkeys) doesn't show increased aggression when crowded, then crowding probably doesn't increase aggressive impulses in primates generally.
Prethinking:
Question type:
Weaken - We need to find information that would reduce our belief in the conclusion that crowding doesn't significantly increase aggressive impulses in primates
Precision of Claims
The conclusion makes a broad claim about ALL primates based on one study of rhesus monkeys, and assumes that coping behaviors mean no aggressive impulses exist
Strategy
Look for ways to show that the monkey study doesn't actually prove crowding doesn't increase aggression in primates. We can attack the reasoning by showing:
- The coping behaviors might actually indicate suppressed aggression rather than lack of aggression
- Monkeys might not be representative of all primates
- There might be other explanations for why the monkeys didn't show overt attacks
'The rhesus monkeys is the species of monkey that is more prone to fighting.' This doesn't weaken the argument effectively. Even if rhesus monkeys are naturally more aggressive, the study still showed they didn't increase attacks when crowded - they increased coping behaviors instead. If anything, this might slightly strengthen the argument because it suggests that even naturally aggressive monkeys don't show increased aggression when crowded. This choice doesn't address the core reasoning flaw.
'Coping behavior was adopted by the crowded monkeys to forestall acts of aggression among them.' This is a powerful weakener. The argument assumes that coping behaviors indicate a lack of aggressive impulses. But if the monkeys were using coping behaviors specifically to PREVENT aggression, then aggressive impulses were actually present - they were just being actively managed. This means crowding DID increase aggressive impulses; the monkeys just handled them differently than rats. This completely undermines the conclusion by showing the monkey evidence actually supports rather than contradicts the crowding-aggression link.
'All the observed forms of coping behavior can be found among rhesus monkeys living in uncrowded conditions.' This doesn't weaken the argument. The key finding was that coping behaviors INCREASED significantly under crowded conditions, not that they were unique to crowding. The fact that these behaviors also exist in uncrowded conditions doesn't change the significance of their increase when monkeys were crowded. This choice misses the point about the comparative increase in frequency.
'Some individual monkeys in the experiment were involved in more attacks than the others.' This is irrelevant to the argument. Individual variation in attack frequency doesn't address the main finding that attacks didn't increase significantly overall when conditions became crowded. The argument is about general patterns, not individual differences. This doesn't challenge the reasoning about whether crowding increases aggressive impulses.
'Some of the rhesus monkeys in the experiment were subjected to levels of crowding that are unlikely to occur in natural circumstances.' This doesn't weaken the argument's logic. Whether the crowding levels were natural or artificial doesn't change the fact that under crowded conditions (however extreme), the monkeys showed increased coping behaviors rather than increased attacks. The argument's reasoning about what this means for aggressive impulses in primates remains intact regardless of how realistic the crowding levels were.