文露　陳小悅

Throughout her career as a neurobiologist1， Peggy Mason has been told over and over that the rats she experiments on are not capable of empathy. Only humans and other primates2 can understand the emotions of another. Most other animals cant， and certainly not beady-eyed3 rats.

But what she was witnessing in the lab was telling her something very different. In experiments， Mason and her colleagues at the University of Chicago were finding that when one rat was placed near another jailed rat， the free rat would open the hatch4 for a rescue—something it wouldnt do for a toy rat. Whats more， when given the choice between saving a fellow rat and some delicious chocolate， the free rat would open both cells and then share.

The study， published in Science in 2011， was a breakthrough. If rats were capable of basic forms of empathy， then perhaps empathy was common—or even universal—among mammals5. Studying animal empathy could give us insight into how human empathy evolved6.

But almost immediately， Masons results met intense skepticism7.

Alex Kacelnik， a behavioral ecologist， argued that Mason was simply projecting humanlike feelings and emotions onto these rat “rescues”—a tendency known as anthropomorphism.8

“We dont have evidence that there is an internal first-person experience that leads the animal to do it，” Kacelnik tells me. “Do they experience any emotion when helping a partner？ It may as well be， but we dont know.”

In a response to Masons study， Kacelnik and his colleagues wrote that tiny ants can also appear as if they are “rescuing” other ants in some situations. But ants are nearly brainless， and few consider them capable of empathy.

Alan Silberberg， a psychologist at American University， also wondered if Mason was inferring too much from the data.9 In his view， the free rat opened the cage for selfish reasons： It liked playing with the other rat. He published a paper replicating Masons design， but with a twist.10 He showed when the rats couldnt play with each other after the trap opened， the free rat wasnt as interested in conducting the jailbreak11.

These criticisms dont mean Masons findings are incorrect. But they do illustrate a core difficulty in studying animal empathy： While its easy to observe animal behavior， its near impossible to confirm the motivations behind that behavior.

The quest to understand animal empathy has been long and fraught， but it isnt trivial.12 If animals can indeed feel emotions like our own， the revelation may one day lead to treatments for conditions where social bonding is difficult—like in autism—or is nonexistent， like in sociopathy.13

We should care whether animals have empathy. It would mean animal brains are not that different from our own.

For decades， scientists trying to study animal empathy have run into a simple fundamental14 problem. Early experiments to prove that animals have empathy were all confounded15 by this limitation.

The wrong conclusion to take away from all these studies is that these rodents16 are humanlike. The right conclusion is that were animal-like.

Frans de Waal is one of the worlds leading primate behavior researchers. Since the 1970s， hes made thousands of observations of primate communities. Hes shown that many primates will console17 one another after fights. Hes seen them hug and kiss. In 2010， he co-authored a paper in the Proceedings of the National Academy of Science compiling data from more than 3，000 observations of chimpanzee fights.18 The paper found that chimps will commonly console the losers of fights—a behavior especially pronounced among chimps with kinship19 bonds.

De Waal thinks its wrongheaded for some scientists to dismiss observations of empathy in animals.20 After all， it makes sense from an evolutionary perspective.21 If human empathy is so robust and adaptive， it must have evolved from more primitive forms.22

If human and animal empathy are the same， it means lessons learned from the brains of animals can be applied to heal23 our own.

Young， a neuroscientist at Emory University， is hopeful his continued work on prairie voles will yield animal models for psychiatric drugs.24 With a good animal model he could， in theory， test whether a drug would make the prairie voles more or less likely to comfort one another. He could test to see if there are certain genes responsible for empathetic behavior， and target those for intervention25.

Perhaps the fluffy， heartsick prairie vole can open that door.26

We still dont know how many animals can actually empathize. But the mounting studies suggest theres a fundamental baseline，27 at least among mammals.

The capacities may vary depending on how animal societies are structured. Chimps and primates are thought to have the most humanlike emotional capacities. Dogs have evolved to live in packs and are attuned to our emotional needs.28 Cats， evolved to be solitary29 hunters， care much less.

But what difference does it make if chimps know why theyre helping out a friend？ Isnt it enough that they engage in the behavior， just like we do？

“Lets say you are living in a house with children， and you are crying， and your children approach you and touch you，” de Waal says. “Youre not， at that moment， thinking， ‘Are they now altruistic30 or selfish when they do this？ That would be a silly distinction. Because your children are responding to your emotions.”

Thats all that really matters.

老鼠有同情心嗎？當同伴身陷囹圄，它們會出手相救嗎？神經(jīng)生物學家經(jīng)實驗發(fā)現(xiàn)，面對分別“關押”著美味巧克力和另一只小伙伴的兩個籠子，外面的小老鼠竟選擇魚和熊掌得兼也——它不但救出了伙伴，還和它一起分享巧克力。然而，它的做法究竟是因為同情籠子里的小鼠，還是因為想讓它出來和自己玩的一己私念呢？讓我們一起來探究動物們的小心思吧。

1. neurobiologist： 神經(jīng)生物學家。

2. primate： 靈長目動物。

3. beady-eyed： 目光銳利的，眼睛如珠的。

4. hatch： 小門，開口。

5. mammal： 哺乳動物。

6. evolve： 進化，演變。

7. skepticism： 懷疑的態(tài)度。

8. 行為生態(tài)學家亞歷克斯·卡塞爾尼克認為，梅森僅僅是人把類似人類的情感安在了老鼠的“救援”行為上，這只是一種眾所周知的擬人論。project sth. onto sth.：（尤指無意識地）投射（自己的感覺給別人）； anthropomorphism： 擬人論。

9. psychologist： 心理學家； infer： 推斷，推論。

10. replicate： 復制；twist： 扭轉，改變。

11. jailbreak： 越獄。

12. quest： 探求；fraught： 令人憂慮的，擔心的；trivial： 不重要的。

13. 如果動物像人類一樣具有情感，那么這一啟示將有可能用于治療社會關系困難或缺失性病癥，如孤獨癥和反社會型人格異常。 revelation： 啟示，揭露；autism： 自閉癥，孤獨癥；sociopathy： 反社會型人格異常。

14. fundamental： 基本的，根本的。

15. confound：（問題等）把……難住，使不知所措。

16. rodent： 嚙齒動物。

17. console： 安慰。

18. Proceedings of the National Academy of Science： 《美國國家科學研究院學報》；compile： 編纂，匯編；chimpanzee： 黑猩猩，下文的chimp為口語用法。

19. kinship： 親屬關系。

20. wrongheaded： 堅持錯誤的，執(zhí)迷不悟的；dismiss： 不予理會，不予考慮。

21. evolutionary： 進化論的，進化的；perspective： 看法，觀點。

22. robust：（觀點、見解）強有力的；adaptive： 適應的，適合的；primitive： 原始的。

23. heal： 治愈，治療。

24. neuroscientist： 神經(jīng)科學家； prairie vole： 草原田鼠；yield： 提供，給予；psychiatric： 精神病治療的。

25. intervention： 介入，干預。

26. fluffy： 毛茸茸的，松軟的； heartsick： 沮喪的，苦惱的。

27. mounting： 逐漸增加的； baseline： 基準，標準。

28. live in packs： 群體生活；be attuned to： 習慣于。

29. solitary： 單獨的，獨居的。

30. altruistic： 無私心的，利他的。