Question Type:
Necessary Assumption
Stimulus Breakdown:
Conclusion: Affection plays the same role in chimp and human communities.
Evidence: Humans face more risks for the sake of those they feel affection for. Chimps face more risks for the sake of those who display feelings of affection.
Answer Anticipation:
This is a COMPARATIVE argument. The author is trying to reason that "Because THIS thing is common to both things, THIS OTHER thing is also common".
Here it's, "Because chimps and humans have RISKING MORE BASED ON AFFECTION in common, the ROLE OF AFFECTION must also be in common." Our job in evaluating comparative arguments is to think "are these fair to compare? or could they in some way be meaningfully different?" If we're reading carefully to see how each half of the comparison matches up, we see that humans and chimps are both expending more risk for a certain trait. But the trait differs. Humans are expending more risk for "those they feel affection for", and chimps are expending more risk for "those who display affection". Humans are protecting the loved. Chimps are protecting the lovers.
Since the author's argument hinges on this comparative element lining up, she has to assume that "risking more for those we love" has a similar role to "risking more for those that love us".
Correct Answer:
B
Answer Choice Analysis:
(A) Extreme: "whenever". Also where did "emotions" come into play? I guess that's adjacent to "displaying affection". If we negated this, and there was at least one instance in which a chimp didn't express its emotions behaviorially, would that hurt the argument. Of course not.
(B) YES. Omigosh, how evil. It's at least appealing because of the soft "at least sometimes" language. Remember, our prephrase was all about the gap between "I have affection for you" and "you show affection for me". This is touching on that gap. If we negate it, it says that "feelings of affection are NEVER reciprocated". That would crush the argument, because it would guarantee that "a chimp DISPLAYING affection" is never a "chimp RECEIVING affection". Since the gap between the chimp example and the human example is this distinction, the author is ruined if we learn that the chimp example he cited could not possibly match up with the human example he cited.
(C) Extreme: "the only". Who cares if there's at least one other reason we protect each other?
(D) Somewhat extreme: "limited to". It sounds softer than "only", but it basically means the same thing. This is saying that chimps are only affectioned to members of their social group. Is it really going to hurt the argument if at least sometimes they're affectionate to something outside their group?
(E) Somewhat extreme: "usually". Did the author need to assume that 51% or more displays of affection are altruistic? Would it hurt the argument if we negated and only 49% of displays of affection are altruistic? Of course not.
Takeaway/Pattern: Mean, mean, mean! The easier parts were recognizing the Comparative structure (one of the three most common reasoning structures, along with Conditional and Causal), and bringing our scrutiny to whether the parts were "fair to compare" or whether they were "meaningfully different". Once we isolated the "receiving" vs. "displaying" affection mismatch, we knew the author was assuming that those different cases were still fair to compare. (B) slightly creeps us towards the idea of them being fair to compare. Negating (B) demolishes the chance of them ever being fair to compare.
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