Much of the evolutionary biology that has grabbed headlines in recent years has sprung from the efforts of sociobiologists and evolutionary psychologists to explain sexual features and behavior--even differences between how men and women think--as evolutionary adaptations. They have looked to the forces of natural selection to explain everything from the mimicry of male mockingbirds to female orgasms among humans. In this controversial book, Richard Francis argues that the utility of this approach is greatly exaggerated. He proposes instead a powerful alternative rooted in the latest findings in evolutionary biology as well as research on the workings of our brains, genes, and hormones.
Exploring various sexual phenomena, Francis exposes fundamental defects in sociobiology and evolutionary psychology, which he traces to their misguided emphasis on "why" questions at the expense of "how" questions. Francis contends that this preoccupation with "why" questions (such as, "Why won't men ask for directions"?) results in a paranoiac mindset and distorted evolutionary explanations. His alternative framework entails a broader conception of what constitutes an evolutionary explanation, one in which both evolutionary history, as embodied in the tree of life, and developmental processes are brought to the foreground. This alternative framework is also better grounded in basic biology.
Deeply learned, consistently persuasive, and always engaging, this book is a welcome antidote to simplistic sociobiological exegeses of animal and human behavior.
Francis writing style and mode of reasoning are profoundly distasteful to me, though others might enjoy it. Francis relishes in contrasting ideas that are in principle mutually consistent and even reinforcing. He draws the intellectual landscape in stark black and white/good and evil, where I generally see the textured grays of creatively contrasting and equally plausible ideas just waiting for some insightful researcher to draw them together into a satisfying explanatory framework. For instance, he depicts the search for the evolutionary origins of social behavior as the "paranoic" search for "teleological explanations." Metaphors relating to psychological illness when speaking of "adaptationist theory" recur incessantly throughout this distinctly intemperate book. Evolutionary psychology, for instance, is flippantly referred to as "evo-psycho."
Even substantively, Francis' method of dealing approaches alternative to his own is, to my mind, shallow and distasteful. I was taught that when disagreeing with a theory, one must first present the theory in as strong and coherent manner as possible, and critique only the most shining and forceful of the theory's ostensible successes. Francis, by contrast, is a bottom-feeder who will launch his missiles against any random representative of the opposing school. Indeed, despite that fact that more than one-third of this book is devoted to notes, index, and bibliography, Francis rarely deigns to cite directly his opponent, rather being content to provide an broad description of the field in question. Typical is the argument relating to the title of book. I don't know of a serious sociobiological argument as to why men don't ask for directions. I don't even know if it's a true fact in search of an explanation. Francis, nevertheless, treats the issue as though it had some intrinsic scientific value.
Francis is smart enough, however, to recognize that he is no match for the greats of the field, so when George Williams, Ronald Fisher, John Maynard Smith, Edward Wilson, or Niko Tinbergen is mentioned, Francis abandons the derogatory bravado and accurately describes the eminently reasonable positions they have taken on the issue of the relationship between evolution and development, adaptation and developmental constraints, and the other topics treated in this book.
The stance taken by Francis is a shame, because there are
super-adaptationists that tend to consider just-so story as adequate explanations, and are loathe to deploy any non-adapationist argument.
Francis' chapter on the mimicking capacity, perhaps the best in the book, is a case in point. Francis defends the sensory exploitation hypothesis ably against the classical runaway selection and costly signaling approaches to modeling mate choice, and effectively defends the theory that the mockingbird's mimicking capacity is simply a by-product of their song-learning versatility. This versatility may itself have adaptive value, but the fact that many bird species that occupy ecological niches similar to that of the mockingbird lack its versatility calls this into question. Indeed, Francis presents a welcome argument to the effect that exotic animal characteristics are unlikely to be adaptation, or they would be more widely share among species share the exotic species' life style and ecological niche. The female hyena's hypertrophied clitoris, the elephant's trunk, hermaphroditism fish, the giraffe's neck, and the human brain may all be examples of characteristics that occurred despite, rather than because of, adaptationist dynamics.
Francis is insistent that sociobiology can only countenance causal forces from physiology and genetic constitution to social constitution, and not vice versa. He contrasts this view, which he calls "misguided materialism" with the developmental view that social organization can affect brain physiology in the short run and genetic structure in the long run. Presumably he never heard of the Baldwin Effect (the term does not appear in his index), despite its centarian age, or the gene-culture coevolutionary models of Cavalli-sforza and Feldman, Boyd and Richerson, and a host of related analyses that have populated the biology, anthropology, and even economics journals for the past quarter century.
Perhaps the most egregious chapter in the book is "Sex without SEX," in which he critiques the adaptationist theory of sexual reproduction. Sexual reproduction is not an adaptation in vertebrates. Rather, he argues, there is a developmental constraint against hermaphrodism, and adaptationists are too blind to see this shining truth. Francis' argument is shabby and incorrect. First, sexual reproduction is extremely costly and could not persist if it did not provide offsetting advantages. Second, as he notes, there are many hermaphrodite fish species, and lizard species as well, but they appear to be evolutionary dead ends. This could be because there are development constraints in vertebrates (there certainly are, in the form of gene imprinting, in mammals), but this remains to be determined. Third, there is no general non-adaptationist theory of sexual reproduction, to my knowledge. He certainly presents none.
Historically, developmentalists have been indifferent or hostile to evolutionary modeling because the do not see how such dynamic historical modelshelp them develop the structural and developmental mechanisms characteristic of living organisms. This stance is no longer fruitful. We now understand that evolutionary models do not prove anything. Rather, they suggest hypotheses to be explored and substantiated. Adaptationist arguments are essential because they suggest the function of homologous and analogous physiological structures. Charting the development of behaviorally-relevant characteristics, such as brain size and social organization, the structure of brains and vocal apparati, using the paleographic evidence, sheds critical light on the path to successfully modeling biological development from the level of cell to that of the complex animal or human society. We increasingly need researchers to explore the synergy between development and evolution. This ill-tempered book could have been written in that spirit, but it was not.
Secondly, the book contains a fairly intense and sustained criticism of some of the current strategies and habits of thought that are applied to these questions in some parts of biology and psychology. Francis thinks that there is far too much emphasis on 'functional explanation,' on the search for the answer to 'why?' questions as opposed to 'how?' questions. Here the book is quite unorthodox and challenging. It is common to think that there is now, in biology, a harmonious division of labor between work on 'how?' questions (work on mechanisms), and work on functional explanations that seek to tell us 'why' the biological world works as it does. It is thought by many that ordinary Darwinism provides us with a straightforward integration of the two kinds of investigation. Francis, in contrast, thinks that many people allow the search for functional explanation to dominate their work. If we understood the 'how' better, we would see that many 'why' questions are transformed or even dissolved.
Thirdly, the book is in many ways a contribution to the philosophy of science. Francis thinks that we need to be much more suspicious of a set of ideas, concepts and strategies that have been embraced by many philosophers of science. Francis thinks that some parts of science have allowed themselves to depart from the materialist pattern of explanation that is appropriate for biology and related sciences. In particular, he thinks that the current enthusiasm for abstact informational and functional concepts is far more antagonistic to materialist and naturalistic projects than people realize.
On these more theoretical and philosophical issues, it is very hard to work out whether Francis is right. I tend to think that he goes too far. (Here I might add that I know the author and have discussed these issues with him, though my own work does not figure in the book.) But the book is extremely valuable as a challenge to some very popular ways of thinking in these areas.
So although the book can be read just as a lively, vivid introduction to the strange sex lives of animals closely related to us, it is also a very deep and careful piece of argumentation. Sometimes Francis is rather polemical in his style, and I can see why some readers (and reviewers) might find the tone a little combative in places. But to me, this makes the book all the more enjoyable to read. I recommend it to anyone interested in sex who also enjoys an intellectual workout.