Frogs, Hot Water and Public Health
April 5, 2010
by S. Todd Stolp MD©
We have probably all heard the description of the allegorical “experiment” in which a frog dropped in hot water will immediately hop out, but a frog in a pot that is slowly heated will recline with hind legs crossed like a vacationer in a spa until succumbing to the heat. This tale is often told to emphasize the human tendency to ignore slow-paced social change while vehemently protesting the same change imposed rapidly. Because April 7 through 11 has been designated Public Health Week, perhaps a close look at the “Boiling Frog” experiment will provide some insights regarding the challenges facing the Public Health sector.
Through the magic of the internet, gathering further research about the poor frog in the experiment is actually quite easy. First, it should be pointed out that, for good reason, animal rights regulations would prohibit the above “experiment” today, and children should be cautioned not to try this experiment at home. However, it turns out that in the 1880s a future president of the American Public Health Association, Professor William Sedgwick, conducted an extensive review of the excitability of the nerves of frogs and quoted the works of Heinzmann from 1872 who had indeed conducted the above experiment with a very slow incremental increase in water temperature in an elaborate system to measure the excitability of the frog. The conclusion was that as long as the incremental change in temperature was slow enough, the evasive muscle movements of the frog were absent. So how does this relate to today’s Public Health challenges, and was it just chance that the reviewer of these studies was a Public Health giant?
To summarize the implications of this experiment, incremental change is ignored if it is slow enough. Consider the incremental change that has occurred in our world over the past 50 years. While we often complain of the dizzying rate of social change over time, it seems that each tiny change that occurs over the short term is in fact embraced. Consider the arrival of fast food restaurants, the ability to purchase a meal for our bodies while at the same time feeding our automobiles at a convenience store, our welcome acceptance of the latest digital device at work and play and our desire for the latest technical excuse to avoid exertion. If we are truly alarmed by the effect these changes are having on our health – and the evidence that this is true is overwhelming – why are these concerns not reflected in our consumer and citizen behavior? Could it be the “Boiling Frog” effect?
Perhaps. However, humans receive much more input from and have much more impact upon our environments than frogs. We can share philosophical views, read the news, watch commercials on T.V., adjust our investments and plan our employment. We can design our cities with a broad range of options when resources allow, choose our meals when choices are available, and select our careers when education is sufficient. These are what are called the “determinants of health,” and play at least as important a role in our health as our access to clinical care, and helping communities to act upon these opportunities is the greatest challenge to public health.
It is interesting to note that before Heinzmann engaged in his research, an European physiologist, Friedrich Goltz, had conducted essentially the same experiment, but Goltz had conducted his research differently. Goltz compared normal frog responses to increasing temperature to the responses of frogs with their brains removed. In his experiment, Goltz used such a rapid change in temperature that the normal frogs actually became irritable and made escape-like movements. The frogs that were “destitute of cerebral hemispheres” did not. Humans, of course, have immeasurably greater cerebral capacity to understand the effects of our environment upon our behavior and audaciously pride ourselves in wielding such magnificent thinking powers. Whether we optimize use of our cerebral resources to use our cognitive and creative skills to keep the temperature in our pot in a survivable range or leap to a new environment will be the ultimate measure of our insight and compassion.