There is a dilemma that must be solved by all beings that form highly cooperative societies. This dilemma is how to obtain the benefits of cooperation without future benefits being destroyed by exploitation, such as by free riders accepting a benefit but not reciprocating. Solving the cooperation/exploitation dilemma is difficult because exploitation is virtually always the ‘winning’ strategy in the short term and can be in the longer term.

Fortunately for us, our ancestors came across solutions that have enabled us to become the incredibly successful social species we are. Evolution encoded some of these solutions in our moral sense and cultural moral codes as “morality”. The science of the last 50 years or so reveals human morality to be elements of cooperation strategies2,3,4,5,9 which have made us “SuperCooperators”6.

Cultural moralities are solutions to the cooperation/exploitation dilemma, but they are also diverse, contradictory, and sometimes strange. Exploitation of out-groups (such as slaves, women, and “others”) has been common. Strange markers of being a moral person such as circumcision, dress and hairstyle, and food and sex taboos have been required.

Properly understood, morality is not a burden; it is an effective means for increasing the benefits of cooperation, especially emotional well-being resulting from sustained cooperation with family, friends, and community.

Could there be a universally moral subset of these “descriptively moral” behaviors (behaviors described as moral in one culture but perhaps not in others)? Even when cooperating to exploit or make war8 on out-groups, we must necessarily begin by solving the cooperation/exploitation dilemma within an in-group. To sustainably obtain these benefits of cooperation, people within this in-group “circle of moral concern”7 are not exploited.

This defines a universal moral principle: “Solve the cooperation/exploitation dilemma without exploiting others in your circle of moral concern”. This principle is universal because it is a necessary component of all cultural moralities, even sub-cultures which restrict in-groups to family or friends and exploit everyone else. We can simplify this universal principle as “Increase the benefits of cooperation without exploiting others”, leaving “others” undefined for the moment.

This universal moral principle is an attractive reference for refining moral codes to better meet shared needs and preferences. It advocates increased cooperation which both increases material goods benefits and triggers the emotional rewards evolution encoded that motivate further cooperation. Because our moral sense was selected for by the benefits of cooperation, these cooperation strategies are innately harmonious with our moral sense. This moral principle is practical. Following common moral norms such as the Golden Rule is universally moral when the benefits of cooperation are increased. But when following such norms would not solve the cooperation/exploitation dilemma, as when dealing with criminals and in wartime, following them would not be moral. Since this universal moral principle defines only moral ‘means’ (actions that increase cooperation’s benefits without exploiting others) and is silent on moral ‘ends’ (what those benefits are), societies are free to define what those benefits of cooperation ought to be and change them as circumstances change. The universal moral principle also sheds light on the morality of two human invented solutions to the cooperation/exploitation dilemma: money economies (which efficiently enable cooperation that produces material goods) and rule of law (which effectively uses force to punish exploiters). Finally, because universally moral means are accurately tracked, this moral principle is a useful objective reference for resolving many moral disputes. (Disputes can persist about how “others”, “exploiting”, ultimate moral ‘ends’, and other implementation details are defined even among people who accept the principle.)

Individuals can benefit from this science by realizing that, properly understood, morality is not a burden; it is an effective means for increasing the benefits of cooperation, especially emotional well-being resulting from sustained cooperation with family, friends, and community. Also, cultural moral norms are best understood not as moral absolutes but as heuristics (usually reliable, but fallible, rules of thumb) for sustainably increasing the benefits of cooperation. Further, if “others” are defined as all people, then all ‘moral’ norms that exploit out-groups contradict the universal moral principle. These include economic systems based on the unfettered pursuit of self-interest leading to exploitation and prohibitions against homosexuality that exploit homosexuals as imaginary threats.

This purely science-based definition of what ‘is’ universally moral appears to be culturally useful independent of any arguments for mysterious1 sources of obligation or moral authority. However, the principle does not answer all moral questions. What benefits for acting morally ought we seek and who ought to be included in “others” who are not to be exploited? Common preferences might be “increased well-being” and “everyone”. But here objective science goes silent; answers to these questions are in the domain of moral philosophy.


  1. Blackford, Russell (2016). The Mystery of Moral Authority. Palgrave Macmillan.
    2. Bowles, S., Gintis, H. (2011). A Cooperative Species: Human Reciprocity and Its Evolution. Princeton University Press.
    3. Curry, O. S. (2007). The conflict-resolution theory of virtue. In W. P. Sinnott-Armstrong (Ed.), Moral Psychology (Vol. I, pp. 251-261). Cambridge, Massachusetts: MIT Press.
    4. Curry, O. S. (2016). Morality as Cooperation: A problem-centred approach. In T. K. Shackelford & R. D. Hansen (Eds.), The Evolution of Morality. Springer.
    5. Harms, W., Skyrms, B. (2010) Evolution of Moral Norms. In Oxford Handbook on the Philosophy of Biology ed. Michael Ruse. Oxford University Press.
    6. Nowak, M., Highfield, R. (2011). SuperCooperators: Altruism, Evolution, and Why We Need Each Other to Succeed. Free Press.
    7. Singer, Peter (1981) The Expanding Circle: Ethics, Evolution, and Moral Progress. Princeton University Press.
    8. Tooby, J., and Cosmides, L. (2010). Groups in Mind: The Coalitional Roots of War and Morality, from Human Morality & Sociality: Evolutionary & Comparative Perspectives, Henrik Høgh-Olesen (Ed.), Palgrave MacMillan, New York, pp. 91-234.
    9. Tomasello, M., & Vaish, A. (2013). Origins of Human Cooperation and Morality. Annual Review of Psychology, 64(1), 231-255.

This article is from TVOL's project titled “This View of Morality: Can an Evolutionary Perspective Reveal a Universal Morality?” You can download a PDF of the project [here], comment on this article below, or comment on the project as a whole in the Summary and Overview.