So, African Americans also are biased against African Americans and in favor of white Americans, showing it doesn't reduce to group favoritism though that probably plays a big role.

所以黑人也是,对黑人有偏见,倾向于白人，这样表明组内偏爱,所起的影响并不大。

耶鲁公开课 - 心理学导论课程节选

I expect that if I add -A to A, I should get the guy who plays the role of 0 in this world, which is the vector of no length.

我希望如果用 -A 加上 A,应该得到一个零矢量,也就是一个没有模长的矢量

耶鲁公开课 - 基础物理课程节选