PrepTest 124, Section 1, Question 22
Doctor: Being overweight has long been linked with(42 more words not shown)
The argument's reasoning is flawed(3 more words not shown)
- Aignores medical opinions(12 more words not shown)
- Bnever adequately defines(5 more words not shown)
- Cdoes not take(13 more words not shown)
- Dholds that if(19 more words not shown)
- Emistakes a merely(7 more words not shown)
Reading the argument
Healthier than whom?
Being healthier than people who are considerably underweight doesn't automatically make someone healthy. The comparison could be between two groups that both have health problems. One group's doing better would still leave us short of the doctor's conclusion.
The opening link between excess weight and health problems doesn't settle what causes those problems. But we can accept the research comparison without resolving that issue. Our concern is what the comparison proves. Looking at just these two groups also leaves out people at other weights. We shouldn't treat this limited comparison as a complete account of health.
What we’re looking for
The flaw question asks us to describe that jump. The doctor concludes that being slightly overweight is enough to be healthy. We have evidence of being healthier than one other group, not evidence that this condition by itself guarantees health. We don't need to decide which weight is healthiest to see the missing step.
Working the answers
- A
What contrary medical opinions did the doctor ignore? We aren't told that there were any. In fact, the doctor acknowledges the earlier link between excess weight and health problems. Our objection works even if the reported research is sound: doing better than another group doesn't establish being healthy.
- B
We don't need a detailed definition of every familiar word. If someone mentions a T-shirt, we don't normally require a definition of that before following the argument. Here, the problem survives any consistent meaning of healthy: being healthier than someone else still doesn't guarantee meeting that standard yourself.
- C
An appropriate weight might differ between people, but the passage already describes people relative to a weight standard: slightly overweight or considerably underweight. It doesn't prescribe one number of pounds for everyone. Even if we set aside individual differences, the jump from a favorable comparison to guaranteed health would remain.
- D
The argument never establishes a condition that guarantees being unhealthy and then declares someone healthy because they lack it. A link with health problems isn't such a guarantee. The actual reasoning compares two groups and turns the relative advantage of one into a claim that its members are healthy.
- ECorrect
Relative means in comparison with something else: these people are healthier than that group. Absolute means the conclusion claims the property itself: these people are healthy. The first doesn't establish the second.
Think of two people who are both unwell. One could be healthier than the other without either being healthy. That is enough to show why the study's comparison doesn't support the doctor's guarantee.
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