Summary 1, without philosophy’s jargon

The primary reason that people have almost always invented and enforced social moralities is that acting morally increases the synergistic benefits of cooperation within groups.

“Altruistic acts that also increase the benefits of cooperation in groups are evolutionarily moral” is the underlying, universal moral principle for virtually all past and present enforced cultural norms (moral standards). This appears to be true no matter how diverse, contradictory, and bizarre these moral standards are or have been in the past.

For example, “Do not steal, lie in court, or murder” advocates altruism in that everyone ought to not “steal, lie in court, or murder”, in order to benefit the group, even at a cost to themselves such as when they really want to “steal, lie in court, or murder” and think doing so would be beneficial. Also, enforced norms for circumcision and prohibitions against eating shrimp are altruistic in that they can be costly to the individual but beneficial for the group as markers of membership in a cooperative subgroup that excludes outsiders.

There is a “Dark Side” to the above universal moral principle, as some truly awful moral standards are consistent with increasing the benefits of cooperation within a subgroup by exploiting or ignoring out-groups.  For example, slave owners (an in-group) cooperating to better exploit slaves (an out-group).  A popular “Dark Side” idea is the claim that out-groups, such as homosexuals or atheists, threaten society and therefore must be punished or at least ostracized. This tactic continues to be popular among people with leadership aspirations because of a human inclination to increase cooperation when faced with threats and to accept the leadership of whoever points out those threats.

The old idea of moral progress being about expanding the circle of who deserves full moral consideration confronts head on this Dark Side of morality and calls it out as immoral. Such moral progress is selected for, in favorable circumstances, by the increased  benefits of cooperation between groups it provides. However, rational justification for not exploiting out groups in any circumstances may require moral wisdom from another source, traditional moral philosophy.

Moral progress also occurs by the invention of improved enforced cultural norms such as “Do unto others as you would have them do unto you” and “human rights to life, liberty, and the pursuit of happiness”. These are much more effective at increasing the benefits of cooperation in groups than “an eye for an eye and a tooth for a tooth”. This moral progress is selected for by increased benefits of cooperation within groups.

Rational justification for groups to consciously apply the above moral principle in selecting norms to be enforced (moral standards) comes from the benefits of understanding  the proper function of social morality is “to increase the benefits of cooperation in groups by advocating altruism”.

With this understanding, horrific enforced cultural norms such as female circumcision, the moral obligation of women to be submissive to men, and other exploitations of out-groups can be exposed as examples of morality’s Dark Side and thrown onto the trash heap of history.

Rational justification for individuals to accept the burdens of acting morally comes from the power of cooperation to, almost always, deliver net benefits to the individual in the long term.  Prominent among these benefits for individuals in modern societies (with rule of law and money economies) are the psychological rewards evolved by our distant ancestors to motivate (by our moral emotions) and reward (by our experience of durable well-being) altruistic cooperation in groups.

Summary 2, with some of philosophy’s jargon

I am proposing a functionalist enforced social morality consistent with Phillip Kitcher’s approach in his 2011 book “The Ethical Project”. Enforced social morality is the sub-category of morality that deals with interactions with other people and is defined by past and present enforced cultural norms (enforced moral standards).  Other self-interested aspects of morality are not addressed even though they are important parts of answers to the broad ethical questions “How should I live?” and “What is good?”

My first major claim is that it is empirically true, in the normal provisional sense of science, that the function of enforced social morality in societies, the primary reason enforced social morality exists, is to “increase the benefits of altruistic cooperation in groups”. Provisional truth is supported by meeting relevant criteria from science such as: 1) no contradiction with known descriptive facts, 2) explanatory power for myriad known facts and puzzles about morality, and 3) unity with the rest of science, notably biological and cultural evolution and game theory. To date, no other proposed function of morality appears competitive in meeting these criteria for truth.

The proposed universal moral principle is “Altruistic acts that also increase the benefits of cooperation in groups are moral”. This is the logically and empirically correct underlying principle of Evolutionary Morality. Previous unfortunate attempts to define Evolutionary Morality underlying principle as increased reproductive  fitness of the group or the species were based on bad science and worse moral philosophy.

It has a robust evolutionary Dark Side.  It is consistent with in-groups cooperating to exploit or ignore out-groups. Recognition of this behavior as immoral has been progressively selected for by the increased benefits of cooperation between groups that recognition provides (in favorable environments). Recognition of this Dark Side class of immoral behavior is the source of the “expanding the circle of who deserves moral consideration” view of moral progress.

As a fact claim, the proposed moral principle entails no imperative oughts, such as David Hume warned against, that are supposedly somehow magically binding regardless of people’s needs and preferences. The proposed moral principle can only be the basis of instrumental oughts, for example: “Based on science from game theory and human psychology, you ought (instrumental ought), almost always, to accept the burdens of Evolutionary Morality if you desire to increase your durable well-being over your lifetime (or desire to increase some other benefit best obtained by cooperation in groups)”.

In the future, perhaps some other instrumental ought regarding some other moral principle, perhaps meeting some different overriding desire, will be more attractive for adoption and practice.  Or perhaps some clever philosopher will convince people of the reality of some imperative ought.

My second major claim is that until either of these above events occurs, accepting the burdens of Evolutionary Morality regarding enforced cultural norms (moral standards) is the most attractive instrumental moral ought available.

Adopting this principle as a moral reference also provides a simple means of sorting out certain moral nonsense such as the idea that you have the same level of obligation to someone you will never meet as to your own family. Obligation by this rule would be so diffuse as to destroy family life and societies. The Evolutionary Morality principle is fully consistent with having different levels of obligation to your family, your friends, you community, and so on up the group composed of all the people in the world.

Adopting the principle also enables exploiting our understanding of the winning altruistic strategies uncovered by game theory for increasing the benefits of cooperation in groups. For example, indirect reciprocity is a powerful winning strategy in the right environments.  Over 2000 years ago, Indirect reciprocity was present in the familiar normative form “Do unto others as you would have them do unto you” which Jesus is quoted as saying summarizes the “law and the prophets” (summarizes morality).  But we can better apply this rule by understanding, from its game theory origins, when it is immoral to follow the Golden Rule. This is when doing so will decrease the benefits of cooperation in groups as in dealing with criminals and in times of war.

Here is the painting The Death of General Warren at the Battle of Bunker Hill. Neither side was strictly following the Golden Rule that day. But both would have argued that they were acting morally. Evolutionary Morality clarifies first why they thought so, and second, why it would have been immoral for the soldiers involved to strictly follow the Golden Rule that day,