Lisle Douglas J - The Pleasure Trap: Mastering the Hidden Force That Undermines Health and Happiness

Dedicated to the heroes of science,
medicine, philosophy, and religionpast
and presentwho have endeavored
to discover and to tell the truth
about health and happiness.

* The benefits of the most touted and expensive interventions (medicines and surgery) are often so disappointing that they are statistically undetectable. (p. 37)

People are often astounded when enlightened about the statistical realities regarding medical procedures. In fact, most physicians are also shocked, as few are aware of the truth about their own intervention techniques. Many of the most popular and touted medical procedures thought to be effective are, in reality, almost totally ineffective. We believe there are two primary reasons for this confusion.

First, few people understand the concept of appropriate experimental control. For example, it is not uncommon for people to think: "Well, my mother had surgery and chemotherapy for her breast cancer, and she is still living 5 years later, so it obviously worked for her!" However, precisely nothing has been demonstrated by this outcome. In reality, one must randomly assign a group of patients either to a treatment group, or to a no-treatment control group. This way, it can be observed how long those treated manage to survive as compared to how long those not treated manage to survive. Not all science requires the same type of control group, but in this case, a no-treatment control group would be required for any inferences about treatment effectiveness.

With most major medical procedures such as most heart surgery and most cancer treatments, the comparison between treatment and no-treatment groups has demonstrated an astonishing degree of ineffectiveness with medical intervention. This statement is extremely well supported by the scientific literature. One may see excellent reviews of the relevant literature in books by John McDougall, M.D., such as McDougall's Medicine: A Challenging Second Opinion, The McDougall Program for Women, and The McDougall Program for a Healthy Heart. However, please do not take this disquieting report as a wholesale rejection of medical techniques, some of which are quite useful. Simply be alerted that for the primary causes of premature death and disability in the U.S. and other industrialized nations, modern medicine offers surprisingly little hope.

Part of the reason that the public is confused is that physicians themselves are confused. Few physicians receive any substantial education in inferential statistical methods. This is a second major reason for the widespread misunderstanding of medical effectiveness. Physicians largely believe in the effectiveness of their procedures despite the overwhelming scientific evidence that the procedures are worthless or near-worthless! There may be a number of reasons for this misunderstanding, but surely one is that few physicians understand the difference between a scientific observation that is statistically significant versus one that is clinically significant.

A given study can show that a procedure is statistically significant and yet that procedure may have essentially no practical significance whatsoever. A classic example is medication for high blood pressure. Although studies have indicated that blood pressure medications have been shown to decrease stroke risk "significantly," the literature touting the scientific support for such medications is extremely misleading to both nave physician and patient. The clinical value to the average patient may be the possibility of perhaps a few days of extended life, with significant side effects and other risks in exchange for this extremely small potential benefit. For example, the difference between a life expectancy of 22 years and 6 months (with no medication) versus 22 years, 7 months (with medication), can easily be statistically significant if the study has sufficient statistical "power" to detect this infinitesimal difference! Very large studies, such as those done on high blood pressure medication, bypass surgery, and breast cancer treatment, have huge sample sizes that lend such studies great statistical power. As a result, even very small real effects (of highly questionable clinical value) are statistically significant. Physicians, hearing about the "scientific support" for such procedures are impressed, and may honestly reassure their patients that the procedures are effective. The unfortunate reality is that most major medical procedures have disappointing small positive effectswhen they have positive effects at all. For an eye-opening review of the effect sizes of many medical procedures see an article by Gregory Meyer et al (2001) in the American Psychologist, entitled "Psychological Testing and Psychological Assessment." (vol. 56, 128-165).

* This bias makes it difficult for us to grasp that dietary excesses are at the root of our modern health problems. (p. 58)

Some readers may be concerned that this paragraph suggests a Lamarckian view of evolution, that is, the idea that such thinking is present within us because our ancestors thought such things and passed that thinking down through the generations. Of course, nothing of the sort happens. What we mean is that the genes that have built the neural design for modern humans were shaped in environments of caloric scarcity. Those ancient individuals who were not naturally anxious about scarcity were not as successful biologically as those who were more vigilant. Therefore the genes that built the brains that were naturally more scarcity-wary are the genes that now proliferate in the human gene pool. For a discussion of how evolutionary processes "design" both the bodies and minds of animal life (including humans), see The Blind Watchmaker by Richard Dawkins. For the reader who is interested in exploring more about how our natural history shaped our current psychology, see The Moral Animal by Robert Wright, and also Evolutionary Psychology: The New Science of the Mind by David Buss.

* This principle is what we have termed the Law of Satiation. (p. 64)

Though the term "Law of Satiation" is our creation, the concept is not new. The fact that animal minds are designed with extremely sensitive homeostatic mechanisms for optimal hunger, thirst, temperature regulation, and other functions has long been understood by physiological psychologists. This is beginning to become more widely recognized in the field of weight regulation science. While there are exceptions to every rule (of course), such as individuals with rare disorders that disrupt the mechanisms of satiation, it is clear that humans are just as well endowed with feeding regulation equipment as any other species. As such, our design will not lead us astray given a diet consistent with our natural history.