PrepTest 142

Incorrect. What matters is how rattlesnakes react to squirrels, not what rattlesnake tails do.

Incorrect. Without relating what attracts squirrels to what scares rattlesnakes, this answer is out of scope.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Some squirrels try to scare rattlesnakes away with their tails. Their tails heat up when they do this. Snakes can detect body heat, so the tail heat probably is a factor in scaring snakes away.

Answer Anticipation:
Strengthen questions tend to deal with correlation/causation flaws, so we should always be on the lookout for one in this question type. Hypotheses, too, are generally causal explanations for an observed phenomenon. Both of these factors are pointing towards the same flaw.

And the conclusion in this case is causal—the squirrel's tail heat probably "plays a role." Is it based on a correlation? Yep—the stimulus notes that the squirrel tail "also" heats up "when" harassing a rattlesnake—establishing a connected timeline establishes a correlation.

Now, this argument does take an extra step in that it establishes that the snake can detect body heat. However, this only makes it possible that the body heat is a factor in scaring the snake—just because they can see the heat doesn't mean it's a part of why the tail puffing is effective. But it at least sets it up so that the theory isn't outlandish because the rattlesnake can't see the tail heat.

Since this is a Strengthen question with a correlation/causation flaw, we should look for an answer that:

(1) Eliminates another possibility (but since the argument says that heat just "plays a role" and isn't the sole cause, this answer is less likely)
(2) Shows more examples of cause and effect going together
(3) Establish a control Ð squirrels that don't heat up their tails that are less effective at scaring away rattlesnakes
(4) An explanation of how this causality would work Ð why the snakes are afraid of heat

Answer Explanation:
This answer choice establishes a correlation between a hot squirrel tail and a defensive reaction from the rattlesnake. While correlation doesn't prove causation, it's evidence of it, and so this answer provides evidence that the rattlesnakes react to squirrel tail heat, strengthening the argument. This falls under both the more examples and control common answers.

Key Takeaway:
Strengthen questions very frequently have arguments with correlation/causation flaws. Hypotheses are generally causal explanations for a phenomenon. When you're asked to strengthen a hypothesis, you're almost certainly going to see a correlation/causation flaw.

Incorrect. Without bringing up how tail heat plays into these other interactions, this answer is out of scope.

Incorrect. The squirrel tails do heat up, and this could have developed via evolution without the squirrel being generally aware of it!