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, although there was an increase in instances of "coping" behavior—such as submissive gestures and avoidance of dominant individuals—attacks did not become any more frequent. Therefore it is not likely that, for any species of monkey, crowding increases aggression as significantly as was seen in rats.
Which of the following, if true, most strengthens 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, although there was an increase in instances of "coping" behavior—such as submissive gestures and avoidance of dominant individuals—attacks did not become any more frequent. |
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| Therefore it is not likely that, for any species of monkey, crowding increases aggression as significantly as was seen in rats. |
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Argument Flow:
The argument starts with rat study evidence showing crowding increases aggression, then presents contrasting monkey study evidence showing crowding doesn't increase attacks, and concludes that this difference probably applies to all monkey species.
Main Conclusion:
Crowding is not likely to increase aggression in any monkey species as significantly as it does in rats.
Logical Structure:
The argument uses comparative evidence between two species to support a generalization. It relies on one rhesus monkey study to conclude something about all monkey species, assuming that what happened with rhesus monkeys represents how all monkeys would react to crowding.
Prethinking:
Question type:
Strengthen - We need to find information that would increase our belief in the conclusion that crowding doesn't significantly increase aggression in monkey species like it does in rats.
Precision of Claims
The argument makes frequency claims (attacks didn't become 'any more frequent' in monkeys vs 'significantly' more in rats) and scope claims (generalizing from rhesus monkeys to 'any species of monkey'). The conclusion specifically compares the magnitude of aggression increase between species.
Strategy
To strengthen this argument, we need information that either:
- Shows rhesus monkeys are representative of monkeys in general regarding aggression responses
- Provides additional evidence that monkeys handle crowding differently than rats
- Shows that the study conditions were fair and comparable between species
This tells us that coping behaviors like submissive gestures exist even when rhesus monkeys aren't crowded. While this provides some context about normal monkey behavior, it doesn't help us understand whether the rhesus monkey findings can be generalized to other monkey species. It doesn't strengthen the conclusion that crowding won't increase aggression in other monkey species like it does in rats.
This shows that rats also displayed avoidance behavior when crowded, similar to what we saw in the monkeys. However, this actually works against the argument by showing similarities between rats and monkeys rather than differences. If anything, this suggests the species might respond more similarly than the argument claims, which would weaken rather than strengthen the conclusion.
This is exactly what we need to strengthen the argument! If rhesus monkeys are the most aggressive type of monkey - responding "to a wider range of stimuli than any other monkeys" - then they represent the strongest possible test case. If even the most aggressive monkeys don't show increased attacks when crowded, we can be much more confident that less aggressive monkey species also won't show this pattern. This makes the generalization from rhesus monkeys to all monkey species much more reliable.
The fact that some individual monkeys were in more attacks than others tells us about individual variation within the study, but doesn't help us generalize from rhesus monkeys to other monkey species. This individual variation doesn't strengthen the argument that crowding won't increase aggression across different monkey species.
Learning that some coping behaviors are similar to behaviors that end attacks provides interesting detail about monkey social dynamics, but doesn't help justify the leap from rhesus monkey findings to conclusions about all monkey species. This doesn't strengthen the core argument about species-wide differences in response to crowding.