(Some members here objected to the conversational style of my earlier post, and to its length. I promised to shorten it and make it contain fewer supporting examples, and shorter explanations on how the connected parts of the reasoning fit. Here is the shorter, more compact version. The lengthy, overly wordy post can be found here:
https://thephilosophyforum.com/discussion/10744/ethics-explained-to-smooth-out-all-wrinkles-in-current-debates-neo-darwinist-approach
)

For the purposes of this post, I define the trigger-response system or situation as this: from time to time a person encounters a dilemma of how to behave. The trigger is the situation that necessitates the decision making. The response is the individual’s actual behaviour ensuing from the trigger.
Morality is one of the deciding factors in dilemmas how to behave in some trigger-response situations.
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Morality eludes objective definition. Its definition relies on subjective experience, it avoids an objective definition.

All moral acts could be reduced to “doing good” save for the “should” part. I.e. doing good is moral if the morally acting person does it out of conviction or compulsion due to “I should do this”, and avoids acts that he or she feels he or she should not do.

There are two trigger-response situations in which the morally acting person finds himself to act morally.

One is what I call involuntary moral acting; the other one is what I call acquired moral acting.

An example of involuntary moral acting is saving one’s child from death or injury, even at the risk of damage to one’s own well-being, or of one’s own death.

An example of acquired moral acting is one’s own aversion to theft.

Involuntary moral acts are found to be unchanged in the widely different cultures of the human population; regardless of religion, race, creed, education level, gender / sex, etc.

Acquired moral acts do vary from culture to culture.

There is no subset of humanity of normal people who would violate the involuntary moral acts. By “normal people” I mean capable people physically and mentally; those who don’t suffer from debilitating challenges, including physical, emotional or mental.

Acquired moral acts, on the other hand, can be and are accepted or not accepted, and violated or not, according to level and strength of the acceptance of suggested required behaviour by the individual in response to prescribed triggers.

Involuntary moral acts are pervasive among all societies, unchanged in required behaviour to the same triggers.

Acquired moral acts are hugely diverse in the triggers (circumstances that compel moral behaviour) and the actual reaction to them.

Both moral (involuntary, and acquired, latter if accepted by the individual) codes bring rewards if followed, and punishment for failure to follow. The reward and punishment both cases originate in the individual’s psyche; no outside influence needs to be exerted. Involuntary morals bring on a much stronger emotional punishment or reward, then the reward/punishment received what acquired morals bring on, for fulfilling of failing to fulfil the suggested moral behaviour for given triggers.

I claim that due to the sharp contrast of defined differences that can be found without exception, between the trigger-response couplets in involuntary and in acquired morals, the two systems are separate.

This conclusion in the above sentence is the crux of my paper. No proof provided... this is a theory. Partially substantiated by the supporting elements in the foregoing. My theory has a pragmatic service function. Once it is accepted by a moral theorist that the theory may be right, then all of a sudden moral arguments fall into place.

Two new definitions are borne from the theory: one is a definition of involuntary morality, the other, the definition of acquired morality.

Thus: Involuntary moral actions include those trigger-response mechanisms, in which the person gets rewarded for fulfilling the required response to the trigger with an overwhelming inner satisfaction; or else he is punished by debilitating guilt, should he fail to fulfil the requirement; and the trigger-response mechanisms are pervasive across the species.

Acquired moral actions include those trigger-response mechanisms which society prescribes for its subjects, or human members; the prescriptions may vary in part or in whole from culture to culture; the person is capable of accepting and internalizing this moral prescription, or else he is able to reject it. Once internalized, the trigger-response situation rewards or punishes the person with inner satisfaction, or with inner guilt, according whether he fulfilled or failed to fulfill the moral response required.