Book Review: Mismatch: Why Our World No Longer Fits Our Bodies

Mismatch: Why Our World No Longer Fits Our Bodies by Peter Gluckman and Mark Hanson.
Oxford University Press, ISBN 978-0-19-280683-3, $39.95, 304 pages.

Do you conceive of yourself as a Pleistocene hunter– gatherer living in an alien environment? If so, you might be intrigued by a book entitled Mismatch: Why Our World No Longer Fits Our Bodies by Peter Gluckman and Mark Hanson.

I was intrigued, and I hoped for a scholarly update on what we have all learned on mismatch from John Bowlby, Ed Wilson, Leda Cosmides, John Tooby, Bill Irons, and others. If you have such an expectation, then Mismatch will disappoint. Mismatch is not a scholarly update on the topic of forager brains operating in supermarkets, banks, and bedrooms. Rather, it is an undisciplined work that covers many topics with uneven levels of scholarship.

Despite these flaws, the book has some merit. First, it is not poorly written. Steve Pinker need not fear that he will have to survive on his academic salary, but in places Mismatch passed the subway test of making my commute seem too short. For example, I appreciated the title of “Is the Mother a Reliable Witness?” for a section on the inferences a fetus makes about future resource availability based on maternal signals sent in utero.[1]

Second, there are interesting facts. Those who want to read as much as possible on evolutionary topics, and are capable of straining the krill, may find some novel data. For example, cretinism is a condition of severely stunted mental and physical growth caused by hypothyroidism. Some populations in the Himalayas had cretinism rates of over 10% because of iodine-deficient hypothyroidism. This is a poignant example of the cost of mismatch. (Iodine injections prevent cretinism in this population as readily as limes prevent scurvy.[2])

Some of the other interesting facts in Mismatch relate to phenotypic plasticity as a means to compete in a wider range of environments. High population density among some amphibians, for example, increases the prevalence of carnivorous morphs (Newman, 1992).[3] These examples tend not to be novel (the amphibian review paper that is cited was published in 1992), but they are fun, and they relate to mismatch.

Third, there are some tantalizing tidbits from recent studies. For example, monozygotic twins show increasingly divergent DNA methylation patterns as a function of age and time spent apart (Fraga et al., 2005). This provides molecular support for the possibility of an epigenetic role in phenotypic plasticity.

Fourth, and finally, Mismatch has a chapter “Coming of Age” with a lengthy discussion on the divergence between women’s age of reproductive competence and actual reproduction. Women increasingly tend to menstruate early and marry late. In what appears to be an understudied aspect of mismatch, women in modern industrialized societies endure long periods of conflict between hormonal drives and parental pleas. In some substantial demographic groups, this prereproductive phase of adult life now approaches onequarter of lifespan.

While Mismatch is not without strengths, it has profound shortcomings. Perhaps most importantly the authors do not appear to be well-situated in the relevant literature on evolution. This manifests in persistent use of language that suggests evolution produces optimal design. The authors ask, “What must an animal do to have optimal fitness?”[4] and state, “A good match would imply an optimal strategy for our life course.”[5] There are also hints of group selection in, for example, stating that development works, in part, “to ensure that the organism is born conforming to the fittest design for the species.”[6]

Beyond language, the text is not well-grounded in the primary literature. For example, the intellectual foundation for mismatch is introduced as follows, “One particular concept, that of the ‘environment of evolutionary adaptedness’, was first introduced by the psychoanalyst John Bowlby and further defined by two evolutionary psychologists, Cosmides and Tooby, to define the selective environment on of the Paleolithic.”[7]

One might expect the highest standards in the section most relevant to the book’s core. However, I find three shortcomings in this section. First, John Bowlby is given appropriate credit, but his original work is not cited (Bowlby, 1969). Second, there is no mention of one of the most significant papers on the concept of an environment of evolutionary adaptedness (EEA), namely, Bill Irons’ “adaptively relevant environment” notion (Irons, 1998).

Third, the paragraph labels the work of Bowlby, Cosmides, and Tooby as “overstated” and “oversimplified” stating that “Not all aspects of human behavior can be interpreted purely as a response to a Stone Age environment.”[8] This critique is diametrically at odds with both the form (not simple) and the content (nuanced) of the work critiqued. For example, in their seminal work, Tooby and Cosmides (1992, p. 83) write, “Every feature of every phenotype is fully and equally codetermined by the interactions of the organism’s genes (embedded in its initial package of zygotic cellular machinery) and its ontogenetic environments—meaning everything else that impinges on it.”

These failures of scholarship on the core idea of the book are troubling. Furthermore, the lack of appropriate grounding in the literature is persistent. On the central topic of the relationship between mismatch and disease, the authors address mental health. They make the strong claim that, “the idea that disease could occur in human populations as part of their normal biology and be induced by their interaction with their seemingly normal environment is relatively new.”[9] In 1984, EO Wilson’s Biophilia made a central point of relating mental health to mismatch stating that, although people in human-made environments may self-report being happy, they would be stripped of “a wide array of experiences that the human brain is peculiarly equipped to receive” (Wilson 1984).

Beyond these issues of language and literature, the book includes unfocused and speculative sections on a wide variety of topics including the evolution of senescence, the extinction of Neanderthals, the origins of large brains and the evolutionary roots of menopause. These discussions do not appear to be novel, nor one fears will they be more connected to the primary literature than the discussion of the EEA.

In summary, Mismatch is an uneven and overreaching book with serious gaps in scholarship. Less sophisticated readers may enjoy its prose, but could probably satisfy their taste for evolutionary thinking in other books. The notion of mismatch itself seems of central importance to industrialized life, and it is disappointing that a book with the title Mismatch does not do a better job on the topic.

Those hungry for more information on mismatch may find satisfaction in rereading Bowlby’s classic work. Here’s a sample to entice from Chapter 4, “Man’s Environment of Evolutionary Adaptedness.” The EEA is “the one that man inhabited for two million years until change of the past few thousand years led to the extraordinary variety of habitats he occupies today…Just as Darwin found it impossible to understand the structure of an orchid flower until he knew what insects flourished and visited it in its environment of adaptedness…we need to turn to anthropological studies of human communities…and field studies of the higher primates.”

References

[1] P. 169.

[2] Pp. 2–3.

[3] Pp. 36–37.

[4] P. 18.

[5] P. 195.

[6] P. 24.

[7] P. 103.

[8] P. 103.

[9] P. 202.