Self-study
Support 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. ████ █████ █████ ████ █ ████████████ ████████████ █████████ █████ ███ ████ ████ ██ █████ ███████████ ██ ██ █████ ████████████ █████ ██████ ███ ████ ███████ ██ ████ █████ ██ ███████ █████ ██████ ████ ████ ████ ████████ ██ ██████████
Summary
The author concludes that affection plays the same role in chimp communities as it does in human communities.
Why does the author believe this? Because of the following:
Humans are more willing to face risks to protect people toward whom they feel affection.
A chimp who displays feelings of affection is more likely to be defended by other chimps than are the chimps who rarely display feelings of affection.
Notable Assumptions
Notice that the premise about humans concerns how humans are more likely to defend people that they feel affection for.
But the premise about chimps concerns how other chimps are more likely to defend a chimp that displays affection. There’s a mismatch!
Displaying affection toward others is different from being someone that others feel affection for. So how do the premises indicate a that affection plays the same role in human and chimp communities?
The author must be assuming that chimps that display affection are more likely to be chimps that others in the group feel affection for. And, that people for whom others feel affection are people who also display affection toward others.
21.
Which one of the following ██ ██ ██████████ ██ █████ ███ ████████ ████████
a
Chimps express their ████████ ████████████ ████████ ████ ████ █████
Not necessary, because the argument concerns only displays of affection. This doesn’t require an opinion about expressions of other kinds of emotions or the frequency of those expressions.
b
Feelings of affection ██ █████ ███████████ ███ ██ █████ █████████ █████████████
Necessary, because if it were not true — if feelings of affection in chimp communities are NEVER reciprocated — then the chimps who display affection toward others are not chimps that others feel affection for. And in that case, the premise about humans doesn’t establish any similarity to chimps. The chimp situation would involve a chimp being more likely to be defended even if the other members don’t feel affection toward that chimp. (B) is necessary to make the chimp situation similar to the human situation.
c
Feelings of affection ███ ███ ████ ██████ ██████ ███████ ████ ██████
Not necessary, because even if there are OTHER reasons that humans protect one another in addition to feelings of affection, affection is still one of the reasons that encourages protection, and affection can still play a similar role among chimps.
d
Expression of affection ██ ██████ ██ ███████ ██ ███████ ██ ███ ██████ █████ ██ █████ ████ ███████
Not necessary, because even if chimps sometimes express affection toward members of other groups, we still know that the chimps can display affection toward other members of its own social group, and that this display is associated with higher chance of being protected by one’s own social group.
e
Feelings of affection, ██ ████ █████ ███ █████ ████████████ ███ ███████ █████████ ███████ ██████████ █████████
Not necessary, because even if feelings of affection are usually displayed through some other behavior that isn’t altruistic, we still know that affection is linked to at least some arguably altruistic behavior (defending others in one’s own group). Affection can play the same role with respect to defense of others in one’s group, even if there are other kinds of behaviors associated with affection.