Logical Reasoning

PT5 · S3 · Q5 Animals with a certain behavioral disorder

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Animals with a certain behavioral disorder have unusually high levels of aluminum in their brain tissue.

Conclusion

Animals can be cured of the disorder by being treated with a silicon-based compound that binds to aluminum and prevents it from affecting the brain tissue.

Evidence

Animals with the disorder have unusually high levels of aluminum in their brain tissue. A silicon-based compound binds to aluminum and prevents it from affecting the brain tissue.

Evaluate

This argument is claiming that using a silicon-based compound to bind aluminum will cure animals of the behavioral disorder because the aluminum is somehow negatively affecting the brain tissue. To support this claim, the author needs to assume that the presence of aluminum in the brain is indeed the culprit behind the disorder and not just coincidentally present in affected animals.

In reasoning terms, the author may be operating with an Assumed Cause. The argument hinges on the idea that aluminum isn't just hanging out in the brain tissue correlatively, but is actually causing the disorder.

Goal

Look for an answer that suggests a causal relationship between aluminum and the disorder, or find an answer that would weaken the argument if it were not true: such as it turning out that aluminum is not to blame for the disorder.

The argument is based on which one of the following assumptions?

Animals with the disorder have
Not Necessary: Invariable levels
This answer is unnecessary because variability in aluminum levels doesn’t undermine the connection between aluminum and the disorder proposed in the argument. The author can still argue that aluminum is problematic even if its levels vary among different animals.
3% picked this
Correct
Aluminum is the cause of
Why this is right
Aluminum is the cause of the disorder rather than merely an effect of it. For the author's argument that treating animals with a silicon-based compound will cure them to hold water, it's vital to the logic of the argument that aluminum is actually causing the disorder. This answer choice confirms that causal link. If aluminum were merely a byproduct of the disorder, neutralizing it might have no effect on the disorder itself. Thus, this assumption is crucial.
Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.
81% picked this
Introducing the compound into the
Too Specific: Side effects
While it's tempting to think a lack of side effects is necessary, the argument is focused on the theoretical cure through binding aluminum. Side effects neither prove nor disprove the compound’s efficacy in binding aluminum to prevent its negative impact.
10% picked this
The amount of the compound
Out of Scope: Species-specific neutralization
The argument doesn't get into specifics about varying compound amounts across species. The underlying logic only requires us to believe that the compound, in general, is effective, which makes this level of detail irrelevant.
1% picked this
Aluminum is never present in
Out of Scope Comparison
The argument does not require us to establish conditions for what’s normal or not in brain tissue beyond the fact that aluminum is at high levels in affected animals. It suffices to know there’s more aluminum than there typically should be in the animals with the disorder.
4% picked this

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