PrepTest 155, Section 2, Question 17
Psychiatrist: Psychological stress is known both to cause(23 more words not shown)
The psychiatrist's argument is most(10 more words not shown)
- AIt presumes without(14 more words not shown)
- BIt presumes, merely(21 more words not shown)
- CIt confuses two(18 more words not shown)
- DIt takes for(18 more words not shown)
- EIt takes for(17 more words not shown)
Reading the argument
Stress can cause both problems without one problem causing the other.
The psychiatrist gives us two effects of psychological stress: negative emotions and impaired physical health. The proposed remedy then targets the emotions, as though those emotions are what carry the harm through to the body. But perhaps stress affects physical health separately. In that case, overcoming the negative emotions wouldn't necessarily remove the source of the physical harm.
What we’re looking for
Picture two branches starting from stress: one leads to negative emotions, and the other leads to worse physical health. That's consistent with the evidence. The psychiatrist instead needs a connection from the emotions to health. For the flaw question, look for an answer saying that having a common cause doesn't establish that one of the two effects influences the other.
Working the answers
- A
This starts with two conditions jointly producing an effect. Our argument starts with one condition—stress—producing two effects: negative emotions and impaired health. The relationship is different before we even reach A's proposed mistake. We need to keep track of which things are causes and which are effects.
- BCorrect
The common cause is psychological stress. The two conditions it causes are negative emotions and impaired physical health. The psychiatrist uses that shared cause to suggest that changing the emotions could improve health. But the two effects might arise independently, so the evidence doesn't establish that causal connection between them.
- C
The argument doesn't say two causes are both required for an effect and then treat them as enough to guarantee it. It gives one cause and two effects. No stated requirement is being confused with a guarantee. This description doesn't match the structure we just traced.
- D
Again, the two conditions aren't presented as working together to produce a shared effect. They are themselves effects of stress. The psychiatrist isn't claiming that two joint causes would each work alone; the unsupported claim is that changing one effect could change the other.
- E
This would be a different mistake. For example, someone might say that stress causes negative emotions, so removing stress guarantees that all negative emotions disappear, overlooking other possible causes. But the psychiatrist doesn't propose removing stress or promise to eliminate an effect. The proposal is to overcome negative emotions to improve physical health, and the missing link is whether the emotions influence health at all.
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