Logical Reasoning

PT118 · S1 · Q12 Biologists have noted reproductive abnormalities

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Biologists have noted reproductive abnormalities in fish that are immediately downstream of paper mills.

Conclusion

Dioxin is probably not the cause of the fish's reproductive abnormalities.

Evidence

Even though the fish recover quickly when the mill shuts down, dioxin decomposes very slowly in the environment (so it would still be in the fish's habitat).

Evaluate

The author's support is extremely weird. In general, if we said "When the mill shuts down, the fish recover", that would make it seem like the mill is responsible for the fish's abnormalities. And this is the opposite of what the author is concluding. So how is that support for the idea that "dioxin from the mill is not the cause"?

Well, it's because when the mill shuts down, that doesn't necessarily mean there's no dioxin in the water any more. The author is suggesting that even though the mill is shut down, there's still dioxin in the water near the mill, since dioxin decomposes very slowly in the environment.

Goal

Most of us would have no idea where to go with this thing (this problem is legendarily tough). But with Weaken we can always take a mindset of

So we can think,

12.

Which one of the following statements, if true, most seriously weakens the argument?

  1. Some of the studies that

    Too Weak

    "Some" is almost always wrong on Strengthen, Weaken, and Paradox. This answer would potentially weaken if we were thinking, "Oh, the source of this research is biased, so we can't trust the results." LSAT doesn't like us to invalidate the potential truth of something just because the source might be biased. But even if we could invalidate "some" of these studies, it sounds like other studies that show the same thing also exist.

    12% picked this

  2. The rate at which dioxin

    Unclear Impact

    There are a lot of wishy-washy wrong answers that say things "fluctuate, vary". They're too muddled or unspecific for us to know what impact they have. We would need to know something specific about how decomposition is different in the area near the paper mill, in order for this to have impact.

    16% picked this

  3. Correct

    Normal river currents carry the

    Why this is right

    The author doesn't think that dioxin is the cause because, in his mind, the fish are recovering (during mill shutdowns) even though they are still being exposed to dioxin (it decomposes very slowly). This answer basically ruins the author's assumption that during a mill shutdown the fish are still being exposed to dioxin.The author was thinking that the dioxin released while the mill was operating would still be immediately downstream of the mill, since it takes dioxin a long time to decompose. But this answer is saying, "no, author, river currents would whisk that dioxin away, so after a few hours of the mill being shut down, the water immediately downstream where these fish live would now be dioxin-free. Thus, if fish are recovering during these periods, it looks like dioxin IS the cause of the abnormalities." Another way to say all this is that we're trying to figure out whether dioxin causes the abnormalities. If there's still dioxin in the water when the mill shuts down, but the fish are somehow recovering, then the author can weaken the idea that dioxin causes abnormalities because this would be Cause w/o Effect (the dioxin is present but the abnormalities are not). But if we get to say that the dioxin is transported away, so there isn't dioxin in the water when the fish are recovering, then we can strengthen the idea that dioxin causes abnormalities because this would be No Cause, No Effect (when the dioxin is absent, the abnormalities are absent).

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

    50% picked this

  4. Some of the fish did

    Too Weak

    This is saying that "at least one fish" didn't recover rapidly. That's way too weak to do anything. That one fish may still have recovered (just not rapidly). Either way, one fish that doesn't recover rapidly isn't really strengthening or weakening the idea of whether dioxin is the cause.

    16% picked this

  5. The connection between hormone concentrations

    No Impact

    This is also very weak. Saying something is not thoroughly understood still leaves room for the idea that it's pretty well understood. And it also seems like if we're saying the science is murky, when it comes to dioxin → weird hormones → reproductive abnormalities, that would probably just help this author impugn the idea that dioxin is the cause.

    6% picked this

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