Scientist: Cross-sections of stalactites - calcite formations deposited on cave ceilings by seeping water - can reveal annual variations in...
GMAT Critical Reasoning : (CR) Questions
Scientist: Cross-sections of stalactites - calcite formations deposited on cave ceilings by seeping water - can reveal annual variations in rainfall in particular areas over hundreds and thousands of years. We often found that when - according to these cross-sections - drought occurred in a particular area, it coincided with the collapse of an ancient society in that area. I hypothesize that drought reduced agricultural productivity in these areas, thereby leaving these societies without the resources needed to handle internal stresses and external threats.
Which of the following, if true, would most weaken the support for the scientist's hypothesis?
Passage Analysis:
| Text from Passage | Analysis |
| Cross-sections of stalactites - calcite formations deposited on cave ceilings by seeping water - can reveal annual variations in rainfall in particular areas over hundreds and thousands of years. |
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| We often found that when - according to these cross-sections - drought occurred in a particular area, it coincided with the collapse of an ancient society in that area. |
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| I hypothesize that drought reduced agricultural productivity in these areas, thereby leaving these societies without the resources needed to handle internal stresses and external threats. |
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Argument Flow:
The scientist starts with a research method (stalactite analysis), presents an observation (drought and collapse coincide), then offers a causal explanation (drought weakens societies through reduced agriculture)
Main Conclusion:
Drought caused ancient societies to collapse by reducing agricultural productivity, which left them unable to handle internal stresses and external threats
Logical Structure:
The argument moves from correlation (drought and collapse happen together) to causation (drought causes collapse through a specific mechanism involving agriculture and societal weakness)
Prethinking:
Question type:
Weaken - We need to find information that would reduce our belief in the scientist's hypothesis that drought caused society collapses by reducing agricultural productivity
Precision of Claims:
The hypothesis makes a specific causal claim: drought → reduced agricultural productivity → societies lack resources to handle stresses → collapse. We need to be precise about which link in this chain we're attacking
Strategy:
To weaken this hypothesis, we need to find alternative explanations for the observed correlation between drought and collapse, or show that the proposed causal mechanism (drought → agriculture → resource shortage → collapse) doesn't work as described. We can attack different parts: maybe droughts didn't actually hurt agriculture much, maybe societies collapsed for other reasons during drought periods, or maybe the causal chain works differently than proposed
This choice actually doesn't weaken the hypothesis effectively. The scientist's argument is based on cases where drought and collapse DID coincide - the hypothesis is trying to explain those specific correlations. The fact that some droughts didn't lead to collapse doesn't contradict the proposed mechanism for cases where collapse did occur during droughts.
This choice misses the mark because the scientist isn't claiming that stalactite data directly shows agricultural output. The stalactites show drought patterns, and the hypothesis proposes that drought would logically reduce agricultural productivity. This doesn't challenge the reasoning that connects drought to reduced farming.
This choice might seem to weaken the argument, but it actually supports the scientist's hypothesis. The hypothesis states that drought left societies unable to 'handle internal stresses and external threats.' Internal power struggles and military raids are exactly the types of stresses and threats mentioned in the hypothesis - this shows the mechanism working as proposed.
This directly contradicts the core mechanism of the scientist's hypothesis. If societies had abundant food and water resources during droughts, then the hypothesis that drought left them 'without the resources needed to handle internal stresses and external threats' cannot be correct. This forces us to look for alternative explanations for the drought-collapse correlation, significantly weakening the proposed causal mechanism.
While this shows that factors other than drought can cause societal collapse, it doesn't weaken the specific hypothesis about drought-related collapses. The scientist's hypothesis is specifically about cases where drought and collapse coincided - the existence of other types of collapse scenarios doesn't invalidate the proposed drought mechanism.