The story that this book tells is of a human body adapted and optimized for hunting and gathering that has been thrust by agricultural and industrial revolutions into conditions for which it is ill-suited. The central idea is that of the “mismatch disease.” The mismatch in question is a mismatch between the lives humans were evolved to lead and the ones that we have developed through cultural and technological progress. The human body is governed by what Nassim Nicholas Taleb calls “anti-fragility” or what biologists call “phenotypic plasticity.” Both terms say that our bodies get stronger when exposed to physical stressors and weaker in the absence of such stressors. We’ve now used culture and technology to reduce exposure to such stressors, while—at the same time—food is more available than ever and is in calorically dense / nutritionally sparse forms. This mismatch accounts for many problems. Of course, technology has also allowed us to reduce our exposure to dirt and germs, and this, after being once a boon, has begun to swing us into dangerous territory.
The 13 chapters (including the introduction) are divided into three parts in a logical manner to address the book’s objective. After an introduction that lays groundwork for understanding human evolution in a broad sense, the first part describes human evolution up to the point where culture became dominant force for our species. It clarifies how we became bipedal, how our diets developed, how we got smart, and the ways in which the aforementioned characteristics are interconnected. The second part shifts from Darwinian evolution to cultural evolution, and—in particular—elucidates the effects that the agricultural and industrial revolutions had on the human body. These cultural forces act much faster than evolution. While some argue that humans aren’t really subject to evolutionary forces anymore, owing to cultural and technological advances, Lieberman points out that Darwinian evolution does still effect humanity, but its effect is muted by comparison to fast-acting cultural developments. The final part looks at humanity in the present and projects out into the future. It considers what effect an over-abundance of energy and a declining need for physical activity have had on our species, and what can be done about it.
This book is thought-provoking, well-organized, and uses narrative evidence and humor to enhance readability. (A discussion of the absurdity of products in the Skymall catalog—e.g. luxury items for pet—is a case in point.) It certainly gives on a good education about human evolution. Furthermore, while there are many books out there that deal with mismatch as a cause of diseases like obesity and diabetes, Lieberman also addresses under-explored issues like postural problems from chairs, the influence of shoes on running gait, and the development of nearsightedness because of our close-focusing ways.
I’d say the book’s greatest flaw comes in its discussions of solutions at the end. The author puts all his eggs in the basket of wholesale solutions aimed to make society as a whole improve, while he could do more to share the details of what individuals can do to solve their own problems. Lieberman considers why natural selection won’t solve problems of mismatch and dysevolution. Then he considers how research and development and educational campaigns can only provide partial solutions. His ultimate solution is suggesting regulatory paternalism—e.g. what economists call Pigovian taxes–taxes designed to change behavior by making bad behavior (in this case sedentary lifestyles and over-eating / malnutrition) more expensive. Perhaps such solutions (which will remain political untenable for the foreseeable future in the US, at least) may be necessary, but one shouldn’t conclude that readers with better information and ways of approaching the problem can’t make a difference. I say this based upon the fact that a substantial (if minority) portion of the population is already doing the right thing—eating right, exercising, and not succumbing to modernity’s creature comforts. I, furthermore, say it as a one trained as an economist who has seen easier attempts at paternalism fail over and over again.
I’d recommend this book. I think it gives the reader insight into the problems caused by being evolved to be one thing while being groomed by culture to be another.