According to scientific experiments, the story suggesting that frogs do not recognize danger and do not escape when gradually heated is inaccurate.
“Boiled Frog” is a famous story. It asserts that if a frog is placed directly into boiling water, it will immediately jump out. However, if placed in cold water and the temperature is raised slowly, the frog will not notice and will remain still until it is cooked. This story is often used to remind people about becoming accustomed to abnormal situations and failing to recognize the dangers they face, or by entrepreneurs to illustrate the strategy of introducing change gradually for success.
Scientists have conducted many boiling frog experiments. (Photo: James Lee/Flickr)
However, how accurate is the boiled frog story? In the 19th century, scientists attempted to answer this question.
In 1869, German physiologist Freidrich Leopold Goltz studied the reactions of healthy frogs and frogs without brains when placed in boiling water. He removed the cerebral hemispheres of the frogs, leaving only a small part intact. These frogs would react when poked, swim when placed in water, and sit upright when placed on their backs.
As Goltz gradually increased the temperature, healthy frogs attempted to jump out of the water at 42 degrees Celsius but were still cooked due to the experimental setup that prevented their escape. Meanwhile, the brainless frogs remained in the water with little movement until the water reached 56 degrees Celsius, at which point they began to exhibit twitching movements.
In 1872, researcher Heinzmann conducted another experiment. He placed frogs on a small platform so that they were partially submerged and still able to escape. He found that in many cases, it was possible to gradually heat the water to 37.5 degrees Celsius without the frogs jumping away. Heinzmann did not increase the temperature beyond this point because previous experiments led him to believe this was the temperature at which frogs became paralyzed before being cooked to death.
Some other researchers also carried out similar experiments, but the results varied depending on the rate of temperature increase in the water. This does not mean that the boiled frog syndrome is accurate. The experimental setup may have prevented the frogs from escaping, or the water temperature may have increased too quickly for the frogs to make any effective escape attempts.
Modern experiments have provided more scientifically accurate results. “The story is completely wrong,” said Victor Hutchinson, a biology professor at the University of Oklahoma, in 2007. “The ‘critical maximum temperature’ of many frog species has been identified by researchers. During this process, the water is heated gradually at a rate of about 1 degree Celsius per minute. As the water temperature rises, frogs become increasingly active in their attempts to escape the hot water. If the size and opening of the container allow the frogs to jump out, they will do so.”
