A chimp who displays feelings of affection toward the other members of its social group is more likely to be defended by these group members from raiders outside of the group—even at the risk of harm to these defenders—than are those chimps who rarely or never display feelings of affection toward their associates. This shows that, from a sociological perspective, affection plays the same role in chimp communities as in human communities, since humans are more willing to face risks to protect those toward whom they have feelings of affection.
Which one of the following is an assumption on which the argument depends?The argument compares chimps with humans. In humans, people take risks to protect those
toward whom they themselves feel affection. But for chimps, we are initially told only that a chimp
shows affection toward others and is then protected by them. The argument therefore assumes that the affection is at least sometimes returned.
(A) Chimps express their emotions behaviorally whenever they feel them.
Incorrect. The argument does not require chimps to display every emotion they feel.
(B) Feelings of affection in chimp communities are at least sometimes reciprocated.
Correct. If the other chimps never felt affection in return, their willingness to protect the affectionate chimp would not show that affection plays the same role as it does among humans. The argument needs at least some reciprocal affection.
(C) Feelings of affection are the only reason humans protect each other.
Incorrect. The passage says humans are more willing to protect people they feel affection toward, not that affection is the only possible reason for protection.
(D) Expression of affection in chimps is limited to members of the social group to which they belong.
Incorrect. Whether chimps also show affection toward outsiders does not affect the comparison being made.
(E) Feelings of affection, in both human and chimp communities, are usually displayed through altruistic behavior.
Incorrect. The argument concerns willingness to take risks to protect others, but it does not require affection to be usually expressed through altruism.
Answer: (B)