人都是自私的,100%正确。但是为了他人去牺牲个人的生命,在基因的水平上来解释这种“利他“行为,还是自私的一种表现。雄性动物有保护弱小的冲动。你看一下非洲的水牛为了同类和狮子打架就知道了。Risking your own life, 没错。If you think you can win without losing it, you will give it a try. But if you think you are not winning, you will give up. 肾上腺素一上来,有时头脑会发热。