Logical Reasoning

PT139 · S1 · Q24 In an effort to reduce underage

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In an effort to reduce underage drinking, the Department of Health has been encouraging adolescents to take a pledge not to drink alcohol until they reach the legal age.

Conclusion (this seems = opinion)

This effort by the Dept of Health to reduce underage drinking seems to be successful.

rephrase: The pledge that they're having adolescents take, "I won't drink alcohol until I'm 21", seems to be causing a reduction in underage drinking.

Evidence (survey found = data)

Many 17 year olds who don't drink took a pledge like this.

Almost all the 17 year olds who do drink never took such a pledge.

Evaluate

The author is looking at experimental / survey data and then assuming something causal in his conclusion, so we can use our Explain Curious Fact framework.

Curious Fact ... why is it that the 17 year olds who don't drink signed a pledge to not drink while the 17 year olds who do drink didn't sign such a pledge?

Author's Explanation ... a 17 year old, by nature, is going to drink alcohol underage. But, if they sign one of these pledges, then they won't. The pledge causes them to not drink.

Notice we have to fill in the blanks of the causal story being assumed. Our next job is to ask the two questions that go with this framework:

1. Could there be an Alternate Explanation for the curious fact? 2. How plausible is the Author's Explanation?

Maybe a different way to explain this survey would be that by the time a kid is 17, they've figured out for themselves whether they want to drink underage. Some do, some don't. When someone from the Dept of Health comes a-knockin' at the door and says,

A non-drinking 17 year old will be like, "Sure, I'll sign the pledge."

A 17 year old who's already drinking or assumes they will be as soon as they get to college will be more like, "No, I'm not making that promise".

We could call the people who sign the pledge a potentially self-selecting sample of 17 year olds who don't drink and don't plan to.

Goal

While an answer could potentially attack the plausibility that the pledge was a causal difference-maker for the 17 year olds who signed it (the 2nd question), Flaw is much more likely to test Alternate Explanations (the 1st question).

So let's look for an answer suggesting an alternate way to explain the data, such as our Reverse Causality scenario in which the teens had already decided on whether or not they were drinkers, and only signed the pledge if they already were planning to not drink.

Or look for the Famous Flaw answer calling out the "correlation to causation" move the author is doing here.

24.

The reasoning in the argument is most vulnerable to criticism because the argument

bases a conclusion about the
Bad Evidence Match
Since this answer is structured, bases a conclusion about X merely on Y we need to ask ourselves if X matches the conclusion and Y matches the evidence. Is the conclusion "about the efficacy of a method to reduce underage drinking"? Sure. The conclusion is saying that the method of "having adolescents say the no-drinking pledge" seems to be effective in having reduced underage drinking. Is the premise "a normative judgment about the morality of underage drinking"? No, it's the results of a survey.
1% picked this
fails to consider that an
Not an Objection
Since the answer starts with fails to consider / overlooks the possibility, we can ask ourselves whether the idea that follows is an Objection. Can we object, "Hey, author --- the pledge has not succeeded in reducing underage drinking. After all, other methods can reduce underage drinking by even more?" No. If the pledge made underage drinking go down at all, then the author's conclusion is 100% true. She didn't say this pledge was the best method. She only claimed that it seems to be having some reductive effect.
1% picked this
Correct
infers from an association between
Why this is right
This names the famous Correlation vs. Causation flaw. Since this answer is structured, infers from Y that X we can ask ourselves if X matches the conclusion and Y matches the evidence. Is the conclusion saying that "the pledging was the cause of refraining from drinking"? Yes. By saying the campaign has been successful, the author means that it has achieved its goal of reducing underage drinking. How did the campaign attempt to reduce underage drinking? By making teens say the pledge. So saying the campaign was successful is equivalent to saying that "making teens say the pledge led to a reduction in underage drinking". Is the evidence pointing to "an association between pledging not to drink and refraining from drinking"? Yes, the survey results involve "taking the pledge" co-varying with "refraining from drinking".
Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.
83% picked this
treats a condition that is
Not Necessary vs. Sufficient
This answer refers to the #1 famous flaw, Necessary vs. Sufficient, in which the author provides a conditional statement in the evidence, and then uses that conditional statement in an illegal reversed or negated way to arrive at his conclusion. There was only one premise here (the survey results) and it wasn't conditional, so there's no way this could match.
5% picked this
confuses the claim that many
Doesn't Confuse / Equivalent Expressions
The author isn't confusing anything in terms of how he thinks about the two different groups of 17 year olds in the survey results. Moreover, the claim "many X's are Y" is equivalent to "many Y's are X". They both mean, "There's at least a handful of things that are both X and Y".
9% picked this

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