The main idea behind Moral Minds: How Nature Designed Our Universal Sense of Right and Wrong, by Marc D. Hauser, is deceptively simple. Our brains are equipped with a moral organ, a collection of innate principles with adjustable parameters, set by the environment to produce one of many possible moral systems. Some endorse capital punishment and oppose abortion while others take the reverse view, the result of different parameter settings on the same principle. Other features of the moral organ are that it requires little stimulus input during development and, fully fledged, can deliver ethical judgments quickly and unconsciously.
The significance of Moral Minds is not in the philosophical progress it provides, but in its extensive review of the empirical literature on the mechanisms, ontogeny, and evolutionary roots of the human moral sense.
In “Knowledge of Language: Its Elements and Origins,” Chomsky (1981) outlines the idea of an innate mental state, common to humans, that enables us to acquire knowledge of grammar. He writes that “this innate endowment consists of a system of principles, each with certain possibilities of parametric variation, and that acquisition of knowing of grammar...is, in part, a matter of setting these parameters...on the basis of presented experience.” If Hauser is correct, Chomsky's universal grammar (known to aficionados as UG) has a baby brother!
The significance of Moral Minds is not in the philosophical progress it provides, but in its extensive review of the empirical literature on the mechanisms, ontogeny, and evolutionary roots of the human moral sense. Hauser is well qualified for this gigantic endeavor. He received his PhD in 1987 from the University of California–Davis for fieldwork on free-ranging vervet monkeys. Since 1992, he has held a faculty position at Harvard University, where he is now a full professor of psychology, organismic and evolutionary biology, and biological anthropology, and a leading authority on primate behavior, cognition, and the evolution of language.
Hauser starts Moral Minds by summarizing some relevant philosophical work on the topic. His approach is ostensibly dialectic: Kant and Hume are juxtaposed to extract two opposing positions, with some sassy sketches (the “Kantian creature,” a limbed torso with a brain as a head, and the “Humean creature,” featuring a heart-shaped appendix) to illustrate the simple point that moral judgments can be either reasoned conclusions or mere emotional responses. Both positions are wrong, Hauser argues, and by sleight of hand he introduces the big-eyed “Rawlsian creature,” after the late John Rawls, a political philosopher and former colleague at Harvard. The Rawlsian creature essentially represents Chomsky's idea of principles and parameters. It computes moral judgments by mere appraisal of events, generated (somehow) by adding up sequences of actions, including their causes and consequences. Why Rawls obtained his privileged position here remains somewhat mysterious. His major work, A Theory of Justice 1971, deals with questions of political obligation, the relationship between individual citizens, and the laws created by states, and one is left to wonder why Hauser did not call his Rawlsian creature by its real name: “the Chomskyan creature.”
The sections that follow crisscross through an extensive literature. Hauser demonstrates his vast knowledge and ability to provide broad, comprehensive coverage of the current state of the art in numerous fields. He reviews experimental economics research to illustrate cross-cultural differences in senses of fairness and conditions for cooperation and punishment. Sections on cognitive development follow, which explain how abilities such as distinguishing between accident and intention are necessary for children's development of a moral sense, in conjunction with general sociocognitive skills such as joint attention, pretend play, understanding of false belief, and the ability to delay gratification. He then looks at the adult brain, and it is obvious why this is important: The survival of the “moral organ” metaphor irrevocably depends on empirical evidence of brain circuits that are especially dedicated to moral judgments. Hauser reviews the neuroimaging literature, but fails to find anything conclusive. He then turns to studies on brain-damaged and mentally disturbed people, with much the same results.“At present, none of these studies pinpoint a uniquely dedicated moral organ, circuitry that is selectively triggered by conflicting moral duties but no other,”he concludes. A final section deals with the evolutionary roots of the human moral sense.
Hauser goes over much of the relevant literature on nonhuman primate behavior and cognition, his own field of expertise. Throughout, Hauser's prose is manifestly casual. To motivate or illustrate moral problems, he retells episodes from mainstream cinema or popular American television shows (e.g.,“Desperate Housewives”), or resorts to artificial moral dilemmas of questionable relevance (“Is it OK to push someone before a train to save five people?”).
More important, what should we make of Hauser's appropriation of Chomsky's theory of principles and parameters to model the human moral sense? I remain unconvinced by this application of Chomsky's ideas for a number of reasons. First, the principles-and-parameter theory does not work with empirical linguistic material (Tomasello 2005), and it is interesting that the idea has now been widely abandoned by generative grammarians. Hauser acknowledges this fact in a footnote, but nevertheless insists on resurrecting the idea, and it never becomes clear why. The idea of innate predispositions, subsequently fine-tuned by the environment, is hardly controversial; birdsong develops along this pattern, as does the emergence of schizophrenia. But this has little to do with the detailed mechanisms proposed by the principles-and-parameters theory.
Second, both language and morality are examples of unconscious knowledge systems, of which there are many more, including mathematics, music, and knowledge of artifacts. Baseball caps are trendy for some and a sign of mediocrity to others. Adolescents deliver such fashion verdicts quickly and unconsciously, a function of their subcultural background. A fundamental question left unanswered is, therefore, in what ways the cognitive processes that deliver moral judgments differ from those that deliver other forms of assessment, including such worldly problems as the trendiness of artifacts.
What needs to be sorted out is the role of generalization abilities and concept formation skills in human knowledge systems—how they interact with innate predispositions, what sort of input they require, how they operate as part of larger knowledge systems, and how these knowledge systems interact with each other. Some of the core cognitive abilities are clearly present in nonhuman primates, as outlined by Hauser's own research (Santos et al. 2001), and one of the book's main merits is that it convincingly points to the potential biological roots of these abilities. Moral Minds also makes it clear how much more empirical and theoretical work is still needed to get even a rudimentary understanding of how nature designed our sense of right and wrong. I would like to hear more, but the notion of universal moral grammar appears to be more of an obstacle than a means of pursuing this journey.