Christoph Droesser, Joe Pechmann, Whit Gibbons, Victor Hutchison

Now you surely have heard the story of the boiling frog that is often told by consultants or activists: If you put a frog in boiling water, he will try to escape. If you put him in cold water and heat it gradually, the frog will remain in place until he’s boiled, because that’s the lesson, to him (and consequently to us) gradual change is not perceivable. Frankly, I don’t buy this. But I am looking for professional advice (and I don’t want to boil frogs). Can you help me with that question?
I have heard the anecdote many times. The situation was presented as an example of how gradual habituation to a devilish situation leads to acceptance of an even worse one. But with a real frog in real water, my bet is that when it began to get uncomfortable the frog would jump out if it could, long before the water started to boil. Nonetheless, consultants, activists, and others who are unaware of gradual environmental problems are responding in the way we like to think a frog acts rather than the way it does.
The legend is entirely incorrect! The ‘critical thermal maxima’ of many species of frogs have been determined by several investigators. In this procedure, the water in which a frog is submerged is heated gradually at about 2 degrees Fahrenheit per minute. As the temperature of the water is gradually increased, the frog will eventually become more and more active in attempts to escape the heated water. If the container size and opening allow the frog to jump out, it will do so.

2 thoughts on “Christoph Droesser, Joe Pechmann, Whit Gibbons, Victor Hutchison

  1. shinichi Post author

    THE LEGEND OF THE BOILING FROG IS JUST A LEGEND

    by Whit Gibbons

    University of Georgia

    November 18, 2002

    http://srel.uga.edu/ecoviews/ecoview021118.htm

    Recently I received a communication about frogs that emphasizes the importance of confirming conventional wisdom and offers a metaphor for the human response to environmental degradation.

    The issue started with an email from Germany. As often happens in scientific inquiry, though the answer to the question was pretty straightforward, arriving at the answer was not. But the easy way out accepting what “everyone knows” more often than not simply perpetuates misinformation. Although finding an answer that destroys an urban myth or a commonly held belief may disappoint some people, we are better off knowing the truth.

    Joe Pechmann at the University of New Orleans, who is a noted amphibian conservation biologist, received a query last month that read: “I am writing a weekly column for Die Zeit, Germany’s major weekly paper, on scientific urban legends that my readers ask me about. Now you surely have heard the story of the boiling frog that is often told by consultants or activists: If you put a frog in boiling water, he will try to escape. If you put him in cold water and heat it gradually, the frog will remain in place until he’s boiled, because that’s the lesson, to him (and consequently to us) gradual change is not perceivable. Frankly, I don’t buy this. But I am looking for professional advice (and I don’t want to boil frogs). Can you help me with that question? Thanks! Christoph Droesser, Hamburg, Germany”

    Joe was not sure what the answer was, so he referred Mr. Droesser to me. I also passed the buck, saying: “I have heard the anecdote many times and actually heard a Baptist preacher give a sermon in Mississippi in which he used the story of a big bullfrog in a bucket of water that was being heated. The situation was presented as an example of how gradual habituation to a devilish situation leads to acceptance of an even worse one. But with a real frog in real water, my bet is that when it began to get uncomfortable the frog would jump out if it could, long before the water started to boil. Nonetheless, consultants, activists, and others who are unaware of gradual environmental problems are responding in the way we like to think a frog acts rather than the way it does.”

    I went on to say, “Although I do not know a data-based answer myself, I am aware of experiments that have been done on responses of amphibians to thermal conditions. In some of the experiments the temperature was gradually raised, so I feel certain someone familiar with those studies would have an impression of what a frog would do as the water warmed up. I am sending your question to Dr. Victor Hutchison at the University of Oklahoma to see what he says. I would be interested to know also.”

    Vic’s answer was as follows: “The legend is entirely incorrect! The ‘critical thermal maxima’ of many species of frogs have been determined by several investigators. In this procedure, the water in which a frog is submerged is heated gradually at about 2 degrees Fahrenheit per minute. As the temperature of the water is gradually increased, the frog will eventually become more and more active in attempts to escape the heated water. If the container size and opening allow the frog to jump out, it will do so.” Naturally, if the frog were not allowed to escape it would eventually begin to show signs of heat stress, muscular spasms, heat rigor, and death.

    So where does that leave us with the metaphor for the human response to environmental degradation? Well the idea that you can induce a frog to remain in boiling water if you start it off in cold water is not true biologically. But that does not diminish the need to keep an eye out for the gradual relaxation of environmental laws and regulations. The metaphor lies in the frog’s ability to escape from the container: if there’s no way out, then the frog’s fate is a foregone conclusion.

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  2. shinichi Post author

    茹でガエルの伝説
    『2匹のカエルを用意し、一方は熱湯に入れ、もう一方は緩やかに昇温する冷水に入れる。すると、前者は直ちに飛び跳ね脱出・生存するのに対し、後者は水温の上昇を知覚できずに死亡する』
    は、やっぱりただの伝説でしかなかった。

    およそ人間は環境適応能力を持つがゆえに、暫時的な変化は万一それが致命的なものであっても、受け入れてしまう傾向が見られる。業績悪化が危機的レベルに迫りつつあるにもかかわらず、低すぎる営業目標達成を祝す経営幹部や、敗色濃厚にもかかわらず、なお好戦的な軍上層部などが「茹でガエル」に例えられる。
    心理学者や経済学者、経営コンサルタントなどが、著作で茹でガエルの話を比喩として使用することがある。

    1869年、ドイツの生理学者フリードリッヒ・ゴルツ(Friedrich Goltz)による脳を切除したカエルを用いた実験が発端と見られる。しかし、ゴルツの実験でも脳のあるカエルは摂氏25度から落ち着かない様子になり、温度が上がるごとに激しくもがき苦しみ42度で死んでしまった。

    1873年、ジョージ・ヘンリー・ルイス(George Henry Lewes)による追試験結果がネイチャーに掲載された。 この実験は、精神の所在(つまり、反射ではない意識)を探ろうとするものだったが、1872年と1875年に生物学面からの反証、つまり十分穏やかに昇温(一例では0.002℃/秒)させれば脱出しない、とする報告が寄せられた。1888年、アメリカの生物学者ウィリアム・トンプソン・セジウィックは、温度変化の速度差が原因と解釈し、これが定着した。

    1960年代の東西冷戦、1980年代の終末論、1990年代には温暖化に関連して取り上げられ、またビジネス業界でも広まった。

    1995年、アメリカのビジネス誌「Fast Company」が、著名なビジネスコンサルタントが著書で取り上げたこの物語を検証する特集記事を掲載した。この中で、細胞生物学者のダグラス・メルトン博士は「熱湯に入れれば飛び出さずに死んでしまうし、冷たい水に入れれば熱くなる前に飛び出してしまう」と答え、国立自然史博物館も同様の回答をしている。

    2002年、ドイツの科学ジャーナリスト、クリストフ・ドレッサーは、ドイツ国内でコンサルタントや活動家が盛んに使用する茹でガエルの話を疑わしいと感じながらも、証明するためにカエルを茹でたくはなかった。困ったドレッサーがアメリカの爬虫両生類学者に質問したことを発端として話が学者仲間に伝わり、ホイット・ギボンズから話を聞いたオクラホマ大学教授の爬虫両生類学者ハッチソンは「その伝説は全てが間違っている。動物学の臨界最高温度調査で、多くの種類のカエルは調べられており、手順として1分間に水の温度を華氏2度ずつ上げるが、温度があがるごとにカエルはますます活発になって温度の上がった水から逃れようとしたことから、蓋が空いていたり器が小さければ逃げる」と回答した。

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