Self-study
As a general rule, the larger a social group of primates, the more time its members spend grooming one another. ███ ████ ███████ ██ ████ ██████ ████████ ██ ███ ███████████ ██ ██████ █████████ ████████████ █████ ████ █████ ████████ █████ ██ ████████ ██████████████ ████ ███ ████ ██ ███ ██████████ ███ ████ ██ ██████ ███████ ██ ███ ██████ █████████████ ████ ███ ████████████ ███████ █████ ████ ███ █████████ █████ ██ ███ █████ ████ █████ █████ ██████ ████ █████ ██████ ███ █████████████ █████ ██ ██████ ████████ █████ █████ ████ ███████ ████████ █████ █████████ █████ ██████ █████ █████████ ██ ████ ████████ ███ ████████
"Surprising" Phenomenon
Why did early humans spend almost no time grooming each other, even though we know they lived in large groups, and the general rule among primates is that the larger the group, the more time spent grooming?
Objective
The correct answer will show why early humans were an exception to the general rule about the relationship between group size and grooming. The correct answer might have something to do with the purpose of grooming, which the stimulus says was to maintain social cohesion among primate group members.
23.
Which one of the following, ██ █████ █████ ██ ████ ██ ███████ ███ ████████ ███████████ █████████ ██████
a
Early humans were ████ ████ ██████ ██ █████ ██████████ ████ ███ ███ ███████ ██ █████ ███████ ████████
We’re trying to explain why humans spent almost no time grooming each other. Grooming one’s self is a different kind of grooming, and there’s no indication self-grooming serves the purpose of social cohesion.
b
Early humans developed ██████████ █████ ████████ █ ████ █████████ ███ ██ ███████████ ██████ ████████ ████ ██████ █████████
This shows early humans had a replacement for social grooming. Because they had languages, they didn’t need to groom as much for the purpose of social cohesion.
c
Early humans were ███ ██ ███████████ ███████ ████ ████ ██ ███ █████ █████████ ███ ████████████ ████ ███ ████ ████ ███ ██████ █████████
The main purpose of social grooming was social cohesion. So, even if humans didn’t need to clean each other as much due to having less hair, we’d still expect significant social grooming for the purpose of social cohesion.
d
While early humans ████████ █████ ██ █████ ███████ █████ ██ ██████ ████████ ████ ████ ██████ ██ █████ ███████
This still tells us early humans lived in large groups. So, we’d still expect a lot of social grooming for the purpose of social cohesion.
e
Many types of ████████ █████ ████ ██████ ████ ██████ █████ █████████ ███████ ███ ███████ ████████ ██████ █████████
If other primates, like humans have large neocortex regions, and engage in lots of social grooming, we’d expect humans to do the same.