Logical Reasoning

PT23 · S3 · Q12 Vitamin XYZ has long been a favorite

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Vitamin XYZ has long been a favorite among health food enthusiasts.

Information

Vitamin XYZ has long been consumed by health food enthusiasts.

Recently, a study fond that those who took lots of XYZ daily for two years showed on average a 40% lower risk of heart disease than did members of a control group.

Researchers corrected for differences in relevant health habits such as diet.

Evaluate

We're looking to combine claims, using Conditional / Causal / Quantitative / Pivot wording, none of which we see.

The 2nd sentence provides a correlation, which is somewhat math-y.

When we read the 2nd sentence and it cites a study whose results showed a correlation between XYZ consumption and lower risk of heart disease, we can probably "hear" the typical conclusion an LSAT author would erroneously derive:

Clearly, taking XYZ lowers your risk of heart disease.

We would be like, "Whoa -- slow your roll, there, Dr. Causality. We don't know for sure that XYZ consumption and lower heart disease risk are correlated because XYZ lowers one's heart disease risk.

Maybe it's reverse causality? (maybe having lower heart disease risk leads someone to be a consumer of XYZ? That sounds pretty weird)

Maybe it's a 3rd factor? (maybe there's some other trait that's connected to both XYZ consumption and lower risk of heart disease -- for example, maybe people who exercise regularly are much more likely to consume XYZ. The exercise is what's lowering their risk of heart disease, but since they are more likely to consume XYZ than are non-exercisers, we still see a correlation between XYZ and lower risk of heart disease".

But that final sentence actually says that they controlled for relevant health habits like more exercise, better diet, etc.

Goal

So it looks like we'd be tempted to draw the conclusion XYZ really is the causal reason for the lower risk of heart disease. We can't prove that it is, but we can certainly support that, and this is a Most Supported question.

But otherwise look for something that restates a derivable truth we know based on the data we were given.

12.

Which one of the following inferences is most supported by the passage?

  1. Taking large amounts of vitamins

    Out of Scope: side effects

    We never spoke about any potential side effects of vitamins, so we can't say anything about whether the tradeoffs are "worth it".

    1% picked this

  2. Correct

    Those who take large doses

    Why this is right

    This reinforces the causal connection we presumed they were going for: taking XYZ lowers your risk of heart disease This answer just packages that concept in the specific wording of the study. People in the study took large amounts of XYZ daily for two years. They had a 40% lower risk of heart disease. Since the researchers corrected for differences in other relevant health habits, that 40% appears to be the result of the XYZ. Thus, it's supportable to say that someone who follows the protocol the subjects in this large study did will have a result that trends in the same direction as those in the study did (this answer doesn't guarantee a full-on 40% reduction in risk of heart disease, but it's confident that someone will get at least some reduction in risk). A reduction in risk of heart disease = an increase in likelihood of avoiding heart disease

    Skill tested: Most Supported · how this choice captures the argument's function is the move to repeat next time.

    69% picked this

  3. Li, who has taken large

    Too Strong / Too Literal: 40%

    We know that people in the study on average had a 40% lower risk. We can't interpret an average this literally and say that, "Any random person who did what they did in the study will have a 40% lower risk".

    14% picked this

  4. Taking large amounts of vitamin

    Too Strong: should / most

    If we accept that taking lots of XYZ for two years will lower our risk of heart disease, then it's definitely something we might consider recommending to people who want or need to lower their risk of heart disease. But we don't know what else XYZ does. Maybe it's bad for the kidneys. Maybe it's very expensive. There are too many unknowns about XYZ for us to go from this paragraph to a recommendation for most adults.

    3% picked this

  5. Health food enthusiasts are probably

    Too Broad

    Too Broad: good health Out of Scope: multiple vitamins The only vitamin we heard about was XYZ. We have no idea what happens when people take large daily doses of multiple vitamins. And we only know part of what XYZ seems to do. It seems to lower risk of heart disease. But what if it does so while increasing the risk of liver disease and kidney failure? Is the net effect of taking XYZ "promoting good health"? We can't say.

    13% picked this

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