原文：The reason we yawn when we see someone else yawn is likely due to mirror neurons in the brain, which fire both when you act and when you observe someone else acting, so my brain is basically copying yours.
译文：看别人打哈欠自己也会打，多半是因为大脑里的镜像神经元，它在你做一件事和看别人做一件事的时候都会亮，说白了就是我的脑在抄你的作业。
