And the kind of social network I'm talking about is not the recent online variety, but rather, the kind of social networks that human beings have been assembling for hundreds of thousands of years, So, I form friendships and co-worker and sibling and relative relationships with other people who in turn have similar relationships with other people.
以及他们为什么要这么做。 这里的社交网络 不是最近网上最近流行的那种 而是， 自从人类从非洲大陆出现之后， 人们几十万年来进行的社交活动。 比如说， 我和其他人建立友谊，同事，兄弟，亲戚的关系， 其他人也和另外其他人建立类似的关系。