在早期的人类社区里，当有人做错了事，在小群体里，有其他人便要惩罚他们。
In those early human communities when someone did something wrong, someone else in the small human group would have to punish them.
人口统计专家研究人口增长趋势来获悉是什么因素导致人类社区的规模和组成的改变。
Demographers study trends in population growth to understand what factors cause changes in the size and make-up of human communities.
作者认为，人类如果脱离他们的社区将很难生存。
According to the author, humans can hardly survive if separated from their community.
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