Logical reasoning PrepTest 142 · Section 4 · Question 26

Incorrect. If anything, this answer suggests an alternative cause for the decline in population—hunting—thus weakening the argument.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:Premise Ð Mourning doves that used to nest in the orchard no longer do after sprinklers were installed
Conclusion Ð Cause: Loss of nesting habitat; Effect Ð Decrease in the mourning-dove population

Answer Anticipation:
This Strengthen question has a causal conclusion, which would normally lead us straight to a correlation/causation flaw unless the premises were themselves causal.

However, something interesting happens when we look at the premises—there is a correlation, but it's not a correlation between the supposed cause and effect. It's a correlation between installing sprinklers and the doves not building nests in the area. And that's a correlation between the supposed cause and, potentially, a cause of that cause. But the conclusion doesn't rely on us having an explanation for why the mourning doves moved out of the orchard—just that they did. The sprinklers are a red herring.

So if the argument isn't using a correlation between two things to justify a causal statement between those two things, what is the flaw here? Well, there's another hint in the conclusion—it discusses an overall decrease in population, and an overall loss of nesting habitat. However, the premises are only about the nearby orchards. While the birds stopped nesting there, there's no indication that they weren't capable of moving somewhere else in the area. If there are other available nesting locations, then the loss of one nesting location can't be responsible for the drop in population. Ruling this possibility out will strengthen the argument.

Answer Explanation:
In stating that there are no other nesting habitats attractive to the birds, the argument establishes that if the orchard is no longer suitable, the birds would have to move along. This strengthens the argument that it was the loss of this nesting habitat that led to the decline in population since we know that the birds are no longer nesting in the orchard, and this answer says they couldn't find any other attractive nesting locations in the area, thus forcing them out.

Key Takeaway:
What a way to end the section. If you picked (C), you're in good company. The LSAT is finding more and more ways to get tricky with causality. Remember that correlation/causation is a jump between two things being correlated and a causal relationship between those two things—the shift here meant that a very tempting trap answer caught a lot of test takers.

Incorrect. This is a very tempting trap answer, and we can see why! It seems like it's providing another example of the cause and effect going together. And if the argument concluded that the sprinklers were responsible for the loss of habitat, then this answer would strengthen that argument. However, that's not the causal relationship that the argument sets out to establish, so this answer doesn't strengthen the argument. (At most, it strengthens a premise, but even the premise doesn't establish a causal relationship between the sprinklers and the mourning doves leaving the orchard.)

Incorrect. First, this answer has to do with feeding the birds, not nesting them. Second, even then, if the birds were leaving the orchard and heading to people's houses, they'd still be in the area, and thus the argument's conclusion wouldn't hold—this cuts against the conclusion.

Incorrect. The stimulus already established that mourning doves lived in the orchards, so this at most provides more context for a premise, not strength for the conclusion.