Darwin and Morality

Image permission granted by Understanding Evolution (http://evolution.berkeley.edu), the UC Museum of Paleontology
By William Irons,
Professor of Anthropology, Northwestern University

Since the appearance of Darwin's The Origin of Species in 1859, the question of what evolution tells us about moral issues has been widely debated. Social Darwinism in the late nineteenth century and early twentieth century provides one answer to this question, the idea of the naturalistic fallacy (first defined by G. E. Moore in 1903), and recent theories by evolutionary biologists (Richard Alexander 1987, Robin Dunbar 1996, and Matt Ridley 1997) have presented quite different answers to this question.

Social Darwinism:

The main author of Social Darwinism, despite its name, is not Darwin. Rather it was Herbert Spencer who developed it as an ethical theory and a political philosophy. After the appearance of The Origin of Species, Spencer quickly reformulated his ethical theory as a logical consequence of the process of natural selection. The core idea of Social Darwinism is that the wealthy and powerful enjoy the privileges they do because they are more fit in terms of the traits favored by natural selection. The poor and powerless have less fit traits and therefore it is best to let them perish since their elimination will represent natural selection favoring fitter traits and the spread of fitter traits is a form of progress. This line of thinking about moral issues, politics, and social policy was used to justify colonialism, extreme laissez-faire capitalism, and aggressive militarism. In any military conflict the fitter army would prevail and this would constitute a form of progress. It also justified withholding assistance from the poor and restriction of immigration to the U. S. from regions of the world deemed to have less fit populations. Social Darwinism was closely allied to eugenics, the idea that society (usually the government) should prevent the "unfit" from reproducing. This led to the enactment, in many U. S. states and in Sweden, of laws mandating the sterilization of those deemed mentally or morally defective. The Nazis carried Social Darwinist logic to an extreme, taking it as their mission to serve the welfare of the superior German race at the expense of less fit races and even to exterminate those other races they deemed enemies of the German race. Thus, in Germany, during the Third Reich, Social Darwinism gave an apparently scientific justification to extreme forms of old-fashioned racism and nationalism.

It is important to note that Darwin declared that he was not himself a Social Darwinist and many early supporters of Darwinism as scientific theory, such as Thomas Huxley, the most effective advocate of the theory of evolution in the latter part of the nineteenth century, also rejected Social Darwinism. Now in the early twenty-first Century, there are no longer any serious advocates of Social Darwinism.

The Naturalistic Fallacy:

The naturalistic fallacy was formulated by the philosopher G. E. Moore in his 1903 book, Principia Ethica. In its contemporary form the naturalistic fallacy basically states that one cannot justify any behavior morally by arguing that it is natural, or that it is favored by natural selection. Evolution guided by natural selection provides explanations of the characteristics of living things, but it cannot tell human beings how they ought to behave. One can easily argue that the worst of human behavior, murder for example, is natural in that it stems from human emotions that are products of past natural selection, but this does not make it moral. Ethics and science represent very different ways of thinking and the two should not be confused. Contemporary theories of the evolutionary origin of morality can help to clarify why this is the case.

The Evolutionary Origin of Morality:

A number of evolutionary theorists have developed theories of the origin of morality, that is, of the human propensity to judge certain forms of behavior as good, worthy of imitation and reward, and other forms as bad, not to be imitated and worthy of punishment. This is the basic sense of right and wrong which occurs in all human beings (rare sociopaths aside) and is a subject of much discussion in all human societies. Strong emotions are involved in these judgments of right and wrong. Different societies have different standards of right and wrong and appeal to different sources, often various religious traditions, to justify these standards. Although some authors argue that underlying the vast cultural variation in moral rules, one can find some broad universal moral principles. The most outstanding example of such a broad universal principle is the golden rule: do onto others as you would have them onto us. However, there is also great disagreement. Slavery was once widely judged to be morally acceptable, and in many traditional societies it is considered desirable for parents to arrange the marriages of their children while they are still very young. In contemporary societies, these practices are roundly condemned. However, there is definitely one ethical universal: human beings everywhere in all past ages, consider moral judgments to be of the utmost importance and expend great energy in teaching, advocating, and debating moral principles.

One biologist, Richard Alexander (1967), presented the theory that, in human evolution, competition between groups favored the formation of larger and larger groups, but the formations of such groups was difficult. As groups became larger, they were increasingly prone to internal conflict. A sense of morality was therefore favored by natural selection because it dampened competition and enhanced cooperation within competing social groups. Somewhat later the primatologist Robin Dunbar (1996) developed a similar theory to the effect that language developed as a way of enhancing cooperation and limiting conflict within social groups in contexts of extensive inter-group competition. Language and morality are of course closely intertwined. The primatologist Frans de Waal (1996) addressed the question of the whether our close relatives the chimpanzees have morality. His conclusion, based on very extensive observation of chimpanzees was that they have many of the elements of human morality. They have a sense of reciprocity, that is the idea that good deeds should be reciprocated and that bad deeds should as well. They have a sense of compassion for other members of their group, a sense that there are social rules that group members must obey, and older dominant chimpanzees often behave in ways, such as breaking up fights, that help to maintain peace within the group. Finally, he concludes that language is the one crucial element of human morality they lack. Without language they cannot teach, advocate and debate moral principles the way humans do. Language, of course, serves many functions among human beings, but one of the more important ones is the ability to formulate and discuss moral principles.

Since the function of morality is to limit conflict and to promote cooperation among human beings, it follows that Social Darwinism makes no sense. It also follows that what natural selection often favors, harsh competition among individuals, cannot be a guide to the moral principles that maintain peace and encourage helping behavior in human social groups. The goal of Social Darwinism was to enhance competition whether between social classes or between nations. In this sense it was the opposite of morality.

There is a negative side to morality as portrayed in this theoretical account. It suggests that morality usually is limited to members of the same social group. This agrees with the findings of anthropology, that in very traditional societies, the moral sphere is limited to members of one’s own social group and does not apply beyond this group. This tendency has been labeled tribalism. Much of ethical thinking since the enlightenment has argued that we must get beyond tribalism, and much of contemporary thought emphasizes the elimination of tribalism and recognition of such concepts as universal human rights. Because human beings are intelligent and flexible in their behavior, there is good reason to believe that we as a species can move beyond tribalism and include all human beings in the moral sphere. Much progress has been made in eliminating tribalism, but much remains to be done.


Alexander, Richard D. 1987. The Biology of Moral Systems. NY: Aldine De Gruyter. (Presents the best, in my opinion, theory of the origin of human morality, and presents an argument that group-group competition was a powerful selective pressure in human evolution.)

Darwin, Charles. 1859. The Origin of Species.

Dunbar, Robin I. M. Grooming, Gossip, and the Evolution of Language. 1996. (A provocative theory of the origin of human language which is very much intertwined with the origin of morality. He focuses on gossip, which has a close if awkward relationship to morality. Most gossip address the question of the morality of particular individuals.)

de Waal, Frans. 1996. Good Natured: The Origins of Right and Wrong in Humans and other Animals. Cambridge, MA: Harvard U. Press. (An excellent exploration of traits in primates that share many of the features of human morality. It sheds considerable light on the origin and nature of human moraltiy.)

Huxley, Thomas H., 1896. Evolution and Ethics; Science and Morals.

Moore, George E., 1903. Principia Ethica.

Radcliffe Richards, Janet. 2000. Human Nature after Darwin: A Philosophical Introduction. London: Routledge. (This book analyzes the logic and ethical implications of claims and counter-claims made during the Darwin wars, the heated debate among scientists in the 1970s and 1980s about the extension of Darwinian theory to the study of human behavior.)

Ridley, Matt. 1997. The Origins of Virtue. New York: Viking. (Readable and insightful account of human morality. The approach is broadly sympathetic to libertarianism, but is compatible with a wide range of political views.)

Segerstrale, Ullica. 2000. Defenders of the Truth: The Battle for Science in the Sociobiology Debate and Beyond. Oxford: Oxford University Press. (History of the "sociobiology debate" and the “Darwin wars.�)

Wright, Robert. 1994. The Moral Animal. New York: Vantage books. (Discusses the application of evolutionary psychology to the study of human morality and also explores the question of whether Darwin himself was a moral person.)


http://en.widipedia.org/wiki/Naturalistic_fallacy (Aug. 23, 2008)

http://en.widipedia.org/wiki/Social_Darwinism (Aug. 23, 2008)

http://library.thinkquest.org/C004367/eh4.shtml (Aug. 23, 2008)

For questions about this essay, please contact onebook@northwestern.edu