NPRから猿が経済学的に合理的な行動をとっている研究について：

Scientist Monkeys Around With The Economy : NPR

We were trying to answer questions about whether monkeys are able to behave in an economic way.

研究のテーマは、猿が経済的な行動をとれるのかということだそうだ。

what would happen if you trained a low-ranking vervet monkey to do things that other vervet monkeys, even high-ranking monkeys, couldn’t do?

これを調べるために、社会的地位の低い猿に特殊なスキルを習得させた場合に、その猿の地位がどう変化するかを調べた。

Roughly an hour after she’d open the container for everyone, she was getting groomed a lot more, as much as a high-ranking monkey, and she no longer had to do hardly any grooming herself. But that was not the most spectacular finding.

猿は貨幣を持っていないが、代わりに毛繕いに関する行動を調べた結果、スキルを持った猿の地位の向上が確認された。

So what then did, is we got a second low-ranking female, trained her to open a second container with apples in it, and then we saw that the value of the first provider dropped, more or less, to the half of what she had before. So now we had a competition between two animals. Both of them could provide this good, these apples, and so the value of the first one dropped down again. And of the second one who was very low at the beginning of the experiment, she went up. And they ended up both in the middle, so to speak.

さらにもう一匹同じような猿に同じスキルを習得させている。この場合にもスキルをもった猿の地位は上昇するが、その上昇は限られる。これはより貴重なスキルを持っている人のほうが競争が少なく大きな利得を得られるという標準的な経済学の結論に対応している。

Animals that cannot form binding contracts, animals that cannot talk about what they want to do or cannot offer verbally or anything – they nevertheless are quite accurate in adapting their behavior to what the market gives them.

monkeys arrive at these economic outcomes not through sitting down and negotiation, but through feeling and emotion.

そしてこの現象には契約も言葉も必要ではない。感情によってそういう風に行動しただけだという。