For years, the primary model of medicine has focused on making people feel good and alleviating uncomfortable symptoms. Don’t get me wrong—I take Excedrin if I have a throbbing headache and I take a daily antihistamine to ward off unpleasant allergic reactions. I’m not that much of a caveman!
This said, the advent of evolutionary medicine (see Nesse & Williams, 1995) has been a total game-changer when it comes to understanding best practices in the health professions. The basic principle of evolutionary medicine is pretty straightforward. The idea is that best practices in health care should always include some understanding of the evolutionary biology that underlies the particular issue at hand.
Perhaps the most conspicuous example of evolutionary medicine in action pertains to pregnancy sickness. Before people like Marge Profet (1992) applied an evolutionary lens to an understanding of the fact that many women become nauseous during pregnancy, the most common way to address pregnancy sickness was to treat it as an unpleasant symptom. So in typical westernized medicine fashion, pharmaceuticals were created and administered. Well, if you know your medical history well, you know the drugs that were created had many adverse long-term effects on developing fetuses. This approach was disastrous.
Profet’s evolutionarily informed approach to pregnancy sickness was different. It took an adaptationist approach—asking if pregnancy sickness might be some kind of biological adaptation—and, if so, we should think about the function that it addresses for the human organism. It turns out that pregnancy sickness acts exactly like an evolutionary adaptation. It is common in women across all cultures. It emerges just at the time when the basic organs are forming in the fetus. And it clearly acts to efficiently (if unpleasantly) remove potential toxins (found, for instance, in bitter vegetables) so as to not harm the baby. Evolutionary adaptation. Bingo.
The entire field of evolutionary medicine looks at issues of health in this way. And it is radically improving our understanding of health issues at breakneck speed.
At SUNY New Paltz, where I teach, we are in the middle of our 10th annual Evolutionary Studies (EvoS) Seminar Series—a series dedicated to providing insights into all kinds of phenomena that have been illuminated from an evolutionary perspective. This semester’s series, coordinated by myself along with Academic Director of EvoS, Dr. Tom Nolen, and our graduate assistant, Rich Holler, is focusing on evolutionary medicine. So far, we have had talks on the basics of evolutionary medicine by Mandy Guitar, the broad applicability of evolutionary medicine by the founder of the field, Randy Nesse, and a talk on evolutionary medicine in action, by renowned local physician, Lauren Vigna. (All of these talks are live-streamed and are freely accessible online.)
As an evolutionary psychologist, I am particularly interested in the way that strides in my particular field are helping advance evolutionary medicine. Below are, based on the talks in our series to date, five ways that work in the field of evolutionary psychology is helping advance work in the field of evolutionary medicine. (For those of you keeping score at home, this is clearly evolutionary psychology helping to make the world a better place in my book!)
1. Making People Healthy versus Making People Feel Good
A common principle in the area of positive psychology rests on the assumption that psychology should focus on making people happy (see Wilkins, 2014). While I have no problem with that in principle, I will say that it is short-sighted, at least. Positive evolutionary psychology, a new version of positive psychology (see Geher & Wedberg, in contract; Geher, 2014) suggests that creating a positive psychological life is not always about happiness. We have negative emotions and inclinations toward pain for a reason! These things are common to the human experience because they were adaptive for our ancestors.
One of the core examples given regarding evolutionary medicine has to do with how to treat a fever. Or, in fact, how to not treat a fever! Sure, fever can be uncomfortable—and when it is too uncomfortable, we may need to take ibuprofen or something similar. This said, we can step back and ask why running a fever is a common response to viruses and bacterial infections. It turns out that the extreme heat associated with fever is designed to kill the infiltrating micro-organisms within our bodies. So if you mask the symptom, you are not letting your body do what it needs to do to help you get better.
Optimal health (be it physical or mental) is not always associated with “feeling good.”
In her talk at New Paltz, Dr. Vigna presented a litany of ways that good sleep has broad-reaching positive health outcomes. It helps with physical repair of the body—it helps with a form of neuronal recharge in our brains. It helps with such things as attention and other basic cognitive functions.
But sleep in modern westernized peoples is totally out of whack! We now have entire disciplines within medicine dedicated to issues of sleep!
Part of the problem has to do with evolutionary mismatch. We have many unnatural things in our lives that have adverse effects on sleep—things that did not exist during the time of human evolution thousands of generations ago. Coffee late in the day, tobacco, alcohol—all of these are modern “conveniences”—and they all play a role in insomnia. And the blinking blue lights of your alarm clock and cell phone are no better. Humans were meant to sleep in the dark—without having coffee with dessert.
3. Ovulation Effects
Many issues specific to women’s health have been documented by this new focus on the evolution and health interface. On this point, a great deal of work has demonstrated that the female ovulatory cycle is a basic part of life as a woman. It has natural behavioral effects that relate to a variety of social outcomes (e.g., ovulating women show increased sex drive (see Geher & Kaufman, 2013).
An implication of all this relates to the large-scale use of hormonal contraceptives. Hormonal contraceptives are highly convenient and effective. This said, they are pretty unnatural at the same time. They essentially trick a woman’s body into thinking that it is pregnant—thus halting the release of the egg each month. It is actually a brilliant technology. That said, it changes internal psychological states along with manifest behavior. A great deal of research has shown that women who do not ovulate behave differently from other women in a host of ways. This is certainly something to think about at the very least.
Dr. Vigna is big into CrossFit. This is not surprising. From an evolutionary perspective, it is clear that modern humans simply do not get the right amount of exercise. Our ancestors in the African savanna were all nomadic—and they would walk and/or run up to about 20 miles in a typical day. We now have “the luxury” of being able to sit at a desk all day.
From an evolutionary perspective—and from pretty much any health-related perspective, this is a problem! So we need to get ourselves to exercise. CrossFit is actually an exercise regimen that is based on an evolutionary approach, including a variety of exercises that are based on an assessment of the kinds of exercises found in pre-westernized cultures (and that likely parallel the exercise regimens of our ancestors).
Perhaps the most conspicuous example of how evolutionary psychology informs health is found in an understanding of diet (see Wolf, 2010). Humans have preferences for foods that are high in fat and high in sugar content—because such foods were rare and were, thus, highly physiologically valuable under ancestral conditions—when drought and famine were common.
Due to modern technologies and advances in agriculture, we now have all kinds of processed foods that include foods that are unnaturally high in sugar and fat content. In fact, in her talk at New Paltz, Mandy Guitar pointed out that the in a typical American diet, over 60% of what is eaten on a daily basis is processed foods. Think about that. You don’t have to scratch your head too hard to see how this translates into the current obesity epidemic and resultant problems such as relatively high rates of cardiovascular disease in westernized (as opposed to non-westernized) cultures.
Bottom Line: As Dr. Vigna says, we are living longer, but we are less healthy.
I’d write more, but I’m going to eat an apple and then go out for a run.
Geher, G., & Wedberg, N. A. (in contract). Positive Evolutionary Psychology: Darwin’s Guide to Living a Richer Life. New York: Oxford University Press.;
Geher, G., & Kaufman, S. B. (2013). Mating intelligence unleashed: The role of the mind in sex, dating, and love. New York: Oxford University Press.
Geher (2014). Evolutionary Psychology 101. New York: Springer.
Nesse RM, Williams GC: Why We Get Sick: The New Science of Darwinian Medicine, Times Books, New York, 1995.
Profet, M. (1992). Pregnancy Sickness as Adaptation: A Deterrent to Maternal Ingestion of Teratogens. The Adapted Mind: Evolutionary Psychology and the Generation of Culture. Oxford University Press. pp. 327–365.
Wilkins (2014); Positive Psychology 101. New York: Springer.
Wolff, R. (2010). The Paleo Solution. Las Vegas, NV. Victory Belt Publishing.