Logical Reasoning

PT148 · S3 · Q14 Researchers recently studied the relationship

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Researchers recently studied the relationship between diet and mood, using a diverse sample of 1,000 adults.

Conclusion

By reducing excessive chocolate consumption, adults can almost certainly improve their mood.

Evidence

In a study of 1,000 diverse adults, it was found that those who ate the most chocolate were the most likely to feel depressed.

Evaluate

Since the author is interpreting the meaning of a study, we can use our Curious Fact / Explanation mindset. The evidence presents a Curious Comparison and the author makes a causal assumption that one thing causes another in order to get to her conclusion.

Curious Fact ... Why were the adults who ate the most chocolate the ones that were most likely to feel depressed?

Author's Explanation ... The chocolate is causing their depression

We need to undress this Conclusion for the bare Cause/Effect claim I just said. If I were to say, I am implying that "Reading Twitter causes more stress".

Whenever we see the Curious Fact / Explanation template, we have two pressure points to consider: 1. Alternate Explanations for the curious fact 2. Plausibility of the Author's Explanation

How else could we explain why the people eating the most chocolate were the most depressed?

Maybe we could say that the depression came first, and eating chocolate is just their coping mechanism when they're depressed? (This common type of alternate explanation is usually called Reverse Causality)

Maybe we could say that the people who eat the most chocolate are people who are unemployed, so the chocolate isn't causing the depression, the being-unemployed is causing both the frequent chocolate snacking and the depression. (This common type of alternate explanation is often called Third Factor)

Goal

If we're doing Flaw and we see Curious Fact / Explanation type arguments, 98% of them will provide correct answers either describing the author's overconfident causal assumption (based on a mere correlation) or they will say the author failed to consider some alternative explanation, such as Reverse Causality or Third Factor.

14.

The argument is most vulnerable to criticism on which one of the following grounds?

  1. It improperly infers from the

    Bad Premise Match

    Whenever we see an answer choice structured, infers from the fact that X that Y Y is the conclusion (the thing being inferred), and X is the evidence (the fact from which we derived our inference). So we ask ourselves whether each part matches. Does the conclusion say that a reduction in the consumption of a substance is likely to eliminate a condition? Close. It says a reduction in the consumption of chocolate is likely to eliminate the condition of worse mood. (It doesn't quite say it will eliminate depression, just improve your mood) But that's close enough that I would consider this part potentially fine and now check the evidence half. DId the evidence say a substance causally contributes to a condition? Nope. It said a substance (chocolate) was correlated with a condition (depression) We have to be able to distinguish between statistical, descriptive correlations most X's are Y ppl who are X are more likely to be Y ppl who are X tend to be Y and actual causal claims X promotes Y X contributes to Y if you want Y, do X

    16% picked this

  2. It draws a conclusion about

    Bad Premise Match Wrong Flaw

    This describes the famous Sampling flaw. We don't have any reason to complain about this sample: a diverse sample of 1000 people is a robust and seemingly representative sample. Is the conclusion about the population as a whole? Kind of ... it's about the population of adults as a whole. Is the premise a sample that is unlikely to be representative? Nope. It might be unrepresentative for some reason, but it's certainly not likely to be that way, if it's a big sample size and a diverse population.

    5% picked this

  3. Correct

    It draws a conclusion about

    Why this is right

    Whenever we see this kind of structure draws a conclusion about X from evidence that merely suggests Y we would proceed to ask ourselves whether X matches the conclusion and whether Y matches the evidence. Was the conclusion about a causal relationship between two phenomena? Definitely. It posits a causal relationship between chocolate and mood. Was the evidence merely suggesting that there's a correlation between chocolate and mood? Yes. In the study, those who ate chocolate were the most likely to feel depressed. It's descriptively accurate. Is it describing a logical problem? Is it bad to draw a conclusion about a causal relationship on the basis of a mere correlation? It is if you're overconfident with your wording. Had the author said, "by reducing chocolate intake, adults can possibly improve their mood", that's far less problematic. The author's confidence in saying "by eating less chocolate, you can almost certainly improve your mood" is far too confident, given that we don't know yet whether the chocolate was the cause of the depression.

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

    77% picked this

  4. It confuses a condition that

    Wrong Flaw

    This describes the famous Necessary vs. Sufficient flaw, in which the author presents a conditional premise and then reaches the conclusion by applying it illegally in a backwards or opposite fashion. Did the premise present a conditional premise? No. Eliminate.

    3% picked this

  5. Its conclusion is worded too

    Bad Conclusion Match

    Is this conclusion worded too vaguely? I understand exactly what it's saying. It's predicting that if I eat less chocolate, my mood will improve. I don't think our complaint can be that it's too vague for me to even evaluate this argument. I definitely was able to evaluate the argument.

    0% picked this

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