PrepTest 142, Section 1, Question 21

What we’re looking for

Working the answers

• A

  A history of regular rewards could affect obedience, but this comparison doesn't isolate the effect of unfairness. We would still need to distinguish a dog reacting to its own missing reward from a dog reacting to another dog's better treatment.

• B
  Correct

  Withhold rewards from both dogs, and the treatment becomes equal while both still miss their treats. Now consider the possible results. If obedience declines even under equal treatment, lack of reward is a plausible explanation without unfairness. If obedience stays high when both go unrewarded but falls when only one does, unequal treatment becomes a better explanation.

  This isn't exactly our proposed single-dog test, but it separates the same two possibilities. That's what makes the answer useful: the result would change how convincing we find the interpretation of the original study.

• C

  Switching which dogs receive treats might tell us about their experience across trials. It doesn't remove the unequal-treatment setup or isolate its effect from simply not receiving a treat. We need a comparison that distinguishes those explanations.

• D

  Greater obedience among rewarded dogs tells us how those dogs respond to a reward. The argument concerns why the unrewarded dogs become less obedient. A change in the other group doesn't settle whether the unrewarded dogs are reacting to inequality or just their own lack of treats.

• E

  The number of repetitions measures how quickly the change occurs. Whether it takes one trial or many, both proposed explanations could remain available. Timing alone doesn't identify which feature of the situation causes the dogs to stop obeying.