Saturday, January 31, 2009

Evolutionary Psychology's Slow Acceptance of Darwinian Morality

One sign of the radical character of Charles Darwin's ideas is that even some of his strongest supporters have rejected much of his thinking. This is clear in the case of Darwin's evolutionary account of morality.

When Darwin first published his naturalistic account of the moral sense in 1871 in The Descent of Man, his friend Thomas Huxley defended it against Darwin's Kantian critics--like Frances Cobbe and 
S. George Mivart--who insisted that morality required a supernatural transcendence of nature.  But later Huxley joined the critics, particularly in his famous 1893 lecture on "Evolution and Ethics." In this lecture, he adopted the Hobbesian-Kantian view of ethics, in which the moral improvement of humanity requires a self-abnegating denial of human nature, because human beings in their natural state are selfish and asocial. Huxley adopted the Kantian concept of culture as a uniquely human realm of activity that transcends biology. He interpreted Darwin's "struggle for existence" as a Hobbesian war of all against all. Because of the "moral indifference of nature," he declared, one could never derive moral values from natural facts. He concluded "that the ethical process of society depends, not on imitating the cosmic process, still less in running away from it, but in combating it," and thus building "an artificial world within the cosmos."

For over a century after Huxley, many of the strongest proponents of Darwinian science have followed Huxley's lead in rejecting Darwin's explanation of morality as rooted in evolved human nature, because they have assumed that human morality belongs to a transcendent realm of cultural artifice and free will that is beyond the natural realm of causal forces open to scientific study.

The publication in 1975 of Edward O. Wilson's book Sociobiology provoked a great controversy, because on the first page of the book, he claimed that ethics was rooted in human biology. He asserted that our deepest intuitions of right and wrong are guided by the emotional control centers of the brain, which evolved through natural selection to help the human animal exploit opportunities and avoid threats in the natural environment.

This attempt to revive Darwin's biological study of morality was rejected by some of the leading theorists of Darwinian science. For example, evolutionary biologist George Williams adopted Huxley's Kantian claim that ethics cannot be rooted in human nature because of the unbridgeable gulf between the selfishness of our natural inclinations and the selflessness of our moral duties. As the only rational and cultural animals, human beings can suppress their natural desires and enter a transcendental realm of pure moral duty.

Richard Dawkins took the same position. When his book The Selfish Gene was published in 1976, most commentators saw it as generally agreeing with Wilson's Sociobiology. But they did not notice that the last paragraph of Dawkin's book asserted a Kantian dualism that implicitly rejected Wilson's sociobiological ethics. Dawkins proclaimed that human beings were unique in their capacity for "deliberately cultivating and nurturing pure, disinterested altruism--something that has no place in nature, something that has never existed before in the whole history of the world." "We alone on earth," Dawkins concluded, "can rebel against the tyranny of the selfish replicators." In a 1997 interview, Dawkins explained: "What I am saying, along with many other people, among them T. H. Huxley, is that in our political and social life we are entitled to throw out Darwinism, to say we don't want to live in a Darwinian world. We may want to live in, say, a socialist world that is very un-Darwinian."

Like Thomas Huxley, Williams, Dawkins, and many other theorists of evolutionary psychology have rejected Wilson's sociobiological ethics because they think that ethics requires a transcendence of human biology through culture and reason. Unlike Wilson and Darwin, therefore, the proponents of evolutionary psychology have generally rejected the idea that biological science can account for the moral conduct of human beings.

In 1996, Wilson gave the keynote address at the annual meeting of the Human Behavior and Evolution Society (HBES) in Evanston, Illinois. This is one of the leading organizations in the world for academic researchers who apply Darwinian theories of human nature to the study of human behavior. It might seem, then, that they should accept Wilson's "sociobiology," which he had defined in the first chapter of Sociobiology as "the systematic study of the biological basis of all social behavior." And yet the members of this organization had decided to use the term "evolutionary psychology" as the label for their intellectual project, while avoiding the term "sociobiology." Wilson's speech in 1996 and their reaction to it made clear that the reason for their uneasiness with Wilson's "sociobiology" was their rejection of his biological account of ethics.

Wilson's speech was entitled "The Unity of Science." He argued that the ultimate aim of human understanding of the world was to achieve a unity of knowledge in which the natural sciences, the social sciences, and the humanities would be brought together into one science. As a crucial part of that unification, ethics would be fully explained in biological terms as rooted in human nature, in the moral emotions or sentiments of the human animal. In 1975, in the very first paragraph of Sociobiology, Wilson has declared that he wanted to explain ethics as ultimately rooted in "the emotional control centers in the hypothalamus and limbic system of the brain," which had been shaped by an evolutionary history of natural selection. In 1996, he was elaborating this idea for his book Consilience: The Unity of Knowledge, which would be published in 1998.

The audience at the HBES convention was shocked by Wilson's speech, because they were disturbed by his suggestion that a science of natural facts could explain the ethics of moral values. After all, isn't there a radical dichotomy between science and ethics, facts and values, is and ought? Isn't it a "naturalistic fallacy" to think that one can infer a moral ought from a natural is? John Beckstrom, the local organizer for the HBES convention, wrote a letter to Wilson after the convention condemning Wilson's speech. Beckstrom insisted on the is/ought dichotomy as enforcing a total separation between natural science and normative ethics. "You seemed to be advocating normative uses of sociobiology," he explained. "If you were, I would have to oppose vigorously your position, and I expect many in attendance with whom I later discussed your speech, would do likewise."

Until recently, most of the leading thinkers in evolutionary psychology have adopted Beckstrom's position, which falls into the tradition of Huxley in rejecting Darwin's biological science of morality. It is notable, therefore, that in recent years, the rapidly accumulating research on the biological bases of morality has become so impressive that some evolutionary psychologists are beginning to concede that Darwin was right, and Huxley was wrong.

One sign of this is how the textbooks in evolutionary psychology are being revised. In the first edition of David Buss's Evolutionary Psychology: The New Science of the Mind, published in 1999, there was nothing said about morality. But beginning with the second edition, published in 2004, Buss added a short section on "The Evolution of Moral Emotions." In the first edition of John Cartwright's Evolution and Human Behavior, published in 2000, there was nothing on morality. But in the second edition, published in 2008, Cartwright added a whole chapter on ethics.

In the Preface to this new edition, Cartwright writes: "It was with some trepidation that I ventured to write a chapter on ethics, but if, as part of the paradigm of naturalism, evolutionary psychology offers to provide a scientific account of the mind in all its manifestations, then it should be able to illuminate the nature of moral reasoning and help to clarify the source of our strong moral passions. After all, it is not scientifically credible that the origin of our moral convictions should lie outside the plane of human nature."

I agree. And I am pleased that some of the leaders in evolutionary psychology are beginning to come around to what some of us recognized long ago--that Darwin was right to see that a complete evolutionary science of nature and human nature must include a naturalistic explanation of morality.

A couple of my recent posts on evolutionary morality can be found
here and here.

1 comment:

Anonymous said...

You may be interested in the recently published book by Stephen Brown, Moral Virtue and Nature: A Defense of Ethical Naturalism. From the recent review at NDPR (, it sounds as though Brown's ideas about the relationships between Darwinian biology and ethics are rather different from yours. In particular, he argues (or so the review reports) that a viable virtue ethics can be defended which takes the 'human function' as the basis of all value, where 'the human function' is understood as genotypic proliferation. To my mind, he seems to be engaged in a ridiculously reductionistic endeavor that treats organisms as gene-machines, but I don't know enough about biology to know whether his philosophical ideas rest on a faulty understanding of biology or just on bad philosophy (whatever one wants to say about his arguments, which I haven't read, it is certainly wrong to think that the only viable form of naturalism in ethics is one which tries to ground all value in the goal of successful reproduction). At any rate, that view is rather different from yours (as I understand it), and it would be interesting to hear what you have to say about it.