Top positive review
One of the best books on human evolution
on March 28, 2001
This ambitious work, the magnum opus of Paul Ehrlich, Bing Professor of Population Studies and of Biological Sciences at Stanford University, and the popular author of the best selling The Population Bomb (1968) and many other works, is quite a challenge for any reviewer. Perhaps I should begin with the footnotes. There are too many of them. On page 32, for example, Ehrlich writes "...twelve populations of a gut bacterium have now been tracked..." footnoting the word "bacterium." When one turns to the back of the book, one finds simply, "Escherichia coli." Perhaps it would be better to have written "Escherichia coli" in the first place! And something needs to be done about letting us know which footnotes are extensions of the text (afterthoughts, clarifications, etc., that we might want to go chasing after) and which are merely references. Of course this is a problem with all extensive works of scholarship. I suggest two sets of notes: one for references and one for clarifications, indicated perhaps by numbers for one and alphabetic letters for the other. There are 100 pages of footnotes here (1,909 footnotes!) and 76 pages of works referenced. The index--a particularly good one, by the way--covers 18 double-columned pages.
Footnotes aside, this is a book that in a sense summarizes a long and much laureled career written by a man whose work and accomplishments we can all appreciate regardless of whether we agree with his sometimes all too politically correct conclusions. Human Natures, despite Ehrlich's careful avoidable of such terminology, is about evolutionary psychology; that is, about how our understanding of evolution and our place as evolved and evolving beings affects how we view ourselves and our prospects. His "human natures" are derived from a survey of a vast literature including the work of anthropologists, ethnologists, sociologists, biologists, sociobiologists, psychologists, evolutionary psychologists, ecologists, demographers, geneticists, behavioral geneticists, historians, etc., etc. (This splintering and proliferation of disciplines as we enter the third millennium of the current era makes one long for consilience!) Most of these disciplines and many others have as their unifying principle the process of evolution. Ehrlich writes in the Preface (p. xi) "I want to show how a greater familiarity with evolution might contribute to our resolving...the human predicament." Ehrlich is referring to cultural evolution as well as biological. His primary thesis, that we are not of one "human nature" but of various "human natures," is implicit throughout. Made explicit on page 227, is his belief that since the beginning of agriculture 10,000 years ago we human beings have been, and continue to be, more subject to the forces of cultural evolution than we are to biological evolution. He writes, "cultural evolution...at this stage of our development begins to swamp the more gradual processes of biological evolution." It's clear that he wants to emphasize cultural evolution because we can do something about it, whereas to change our biological nature would involve human genetic engineering, a process that Ehrlich is understandably loathe to endorse (see especially page 66).
Ehrlich argues strongly for the plasticity of human behavior. He doesn't like generalizations about innate behavior. This can be seen particularly in his analysis of the causes of war in the Chapter 11. He insists with some exasperation that "It is senseless from any viewpoint for people to keep acting as if it were either possible or pertinent to determine whether human beings are innately aggressive or innately pacific" (p. 264). Ehrlich wants to encourage the idea that education can lead to more desirable behaviors. If our behavior is innate, then perhaps we can't be blamed for it, and furthermore (and worse) we can't do anything about it in terms of education, etc. It is this fatalism that Ehrlich is preaching against.
In short, Ehrlich takes what might be considered a caring, "liberal," politically correct view of human nature as opposed to some others who see us merely acting out our genetically and culturally derived destinies. His position is comforting, but strange to say I really see little or no difference between his PC version of "human natures" and, e.g., Edward O. Wilson's much maligned amoral view. I think a lot of the differences are really matters of terminology and emphasis.
I want to add a couple of clarifications. Apparently Ehrlich is unaware of the full significance of "the handicap principle"advanced by Amotz and Avishag Zahavi in their book of the same name (1997) which in part explains altruism beyond kinship and reciprocity, namely that altruism is sometimes an advertisement to potential mates of one's fitness. Also in the chapter entitled "Why Men Rule" Ehrlich points to men being bigger as one of the reasons they rule, and to their being freer (because they have less of a reproductive burden) as another. But as Bobbi Low has pointed out in her Why Sex Matters (2000) men rule because there is no reproductive advantage to be gained by women in taking the reigns of power. Whereas men have been able to gain greater sexual access to females by becoming rulers and thereby increase their reproductive fitness (Bill Clinton, notwithstanding), women gain little to nothing in securing access to more males.
Also there is the matter of the synchronization of menstrual cycles by women living together discussed on page 182. Ehrlich says the evolutionary significance is unknown. Actually it's fairly clear: in a harem situation if the females become fertile all at the same time, this provides an opportunity to more broadly mix the gene pool because the harem master can't possibly do it all himself, and so other males may get an opportunity. This embarrassment of riches for the harem master reminds me of the walnut tree producing so many seeds in a boon year that the squirrels can't possible eat them all.
This is a great book engagingly written by a man at the pinnacle of his career, a man I admire and respect.