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Kindness could be maladaptive, occurring at the wrong time and wrong place.
为什么会有"过头"的kindness？比如照顾患alzheimer的亲人，或者帮助不认识的陌生人？人为什么要做没有回报的事？
In none of these cases is there much chance of repayment, whereas evolutionary theory insists that altruism should benefit either blood relatives or those willing and able to return the favor. A dying spouse doesn’t fit the bill.
这种“过头”的kindness不是人类的专利，在黑猩猩中也存在——曾有过黑猩猩收养community里的孤儿的事情。

De waal认为这是"kind" traits的“副作用”
 Many traits evolved for one reason yet have come to serve others as well. I have never heard anyone call fingers gliding over a piano “a mistake,” so why apply this sort of language to altruism?

尼采对“副作用”的解释:
 Friedrich Nietzsche warned that the emergence of something is never to be confused with its acquired purposes: “Anything in existence, having somehow come about, is continually interpreted anew, requisitioned anew, transformed and redirected to a new purpose.”
An item’s history has limited relevance in the here and now. 

或许，使得人们帮助陌生人的品质是通过某种"自私"的方式进化出来的，但这并不能妨碍这些品质让人做无私的事情。
Nothing keeps me from empathizing with a stranded whale and joining efforts to haul it back to the ocean, even if human empathy didn’t come into existence with whales in mind.