Q15 - In the winter

by **smiller** Fri Nov 10, 2017 9:51 am

Question Type:
Procedure

Stimulus Breakdown:
The stimulus starts out almost like an Explain a Result question, with a paradox. Why do ravens encourage other ravens to share their food when it seems like they would benefit from keeping it for themselves? Are ravens altruistic? (It wouldn't be too surprising. Some birds are wicked smart, so why not throw a little altruism into the mix?)

Bernd Heinrich decides to study this behavior. The question stem is specifically asking about this study, so we should pay attention to any discovery that Heinrich makes. What does he discover? Apparently, mated pairs of ravens are jerks, and try to prevent young ravens from eating. As one does, the young ravens form gangs to steal delicious carcasses from the mated pairs.

Answer Anticipation:
It seems like Heinrich's study showed a different side of the ravens. They aren't kindly inviting others to the table, but are forming gangs to take food from older ravens. It seems like Heinrich's study would lead to a different interpretation of the raven's behavior than the interpretation described at the beginning of the stimulus. Altruistic? Nevermore!

Correct answer:
(B)

Answer choice analysis:
(A) Unsupported: We don't know if Heinrich proposed two alternative hypotheses. We're only told about his observations.

(B) Correct: This matches the important features of Heinrich's study. He partially confirmed earlier observations, the reports of ravens sharing food. However, his study leads us to believe that the ravens are doing this to protect their own interests, not to be altruistic.

(C) Unsupported: Again, we don't know if Heinrich himself proposed any theories, or confirmed them through observations. We only know that he became interested in the ravens' behavior, and started observing them.

(D) Unsupported: We don't know about methods used in earlier studies.

(E) Unsupported: We don't know if Heinrich was repeating previous studies, and we don't know if his observational data was more limited.

Takeaway/Pattern:
We're asked to choose the answer that "best" describes Heinrich's study. The stimulus doesn't explicitly state that there was a "radical reinterpretation" of earlier studies, but it seems like that could very well happen. More importantly, the other answers contain details which aren't supported at all by the stimulus.

#officialexplanation