Logical reasoning PrepTest 149 · Section 4 · Question 8

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Female guppies showed a preference for male guppies with more orange, and males tended to show them their most orange side, so male guppies can change their behavior in response to feedback.

Answer Anticipation:
While it's subtle here, this argument jumps from correlation to causation. The conclusion is causal—female guppy behavior changes male behavior. The premises, however, are based on correlations—female guppies show a preference, and male guppies seem to behave in a way that meets that preference. However, there's no indication that the preference is the driving force behind the male guppy behavior—they may just like showing off their orange, or there may be something else that causes both one side to be more orange and that side to be the preferred side they show to the females. Since we're trying to strengthen this correlation/causation argument, we should look for answers that:

(1) Eliminate alternative causes
(2) Shows more examples of cause and effect going together
(3) Removes the cause and sees the effect disappear or reduced significantly

Answer Explanation:
A model wouldn't have behavior cues as live female guppies would, so this answer removes the supposed cause. When that happened, it saw the effect (male guppies showing one side over another) to disappear. By highlighting an example where the supposed cause was taken away and the effect disappeared, this answer strengthens the causal relationship in the stimulus.

Key Takeaway:
If you're having trouble spotting the flaw in a Strengthen/Weaken question's stimulus, and the conclusion is causal, you're probably looking at a correlation/causation flaw. Here, language such as "tended to" highlights that the premises are correlative.

Incorrect. What is true of "many other species" won't impact an argument about one specific species—it's just not strong enough without a premise relating these other species to the guppies.

Incorrect. The stimulus is about the reaction of male guppies to female guppy behavior, not between the level of orange pigmentation and reproductive success, so this answer is out of scope. Additionally, ignoring that, there being no studies done in an area almost certainly won't strengthen an argument.

Incorrect. The appearance of female guppies is irrelevant to an argument about behavior changes of male guppies to female guppy behavior. Only if female guppy coloring was connected to those male behavior changes could this answer be relevant.

Incorrect. It's unclear if this would make the experiment better or worse, so it's unclear what impact—if any—this would have on the argument.