How did evolution arrive at the notion of guilt and shame

With the emergence of a capacity to make and follow normative judgments, reinforced by coevolved reactive emotions such as guilt and resentment, and the development of rules and social practices promoting and enforcing group loyalty and cooperation, a new psychological mechanism came into being for reinforcing the previously unstable altruistic tendencies and promoting large-scale social cohesion and stability. 

The advantages of membership in coalitions and subcoalitions would be conferred on hominins who had facility with such normative guidance—including a strong sense of obligation and tendency toward social compliance—and who thus acted consistently on these altruistic tendencies, acquiring the reputation for being good coalition partners and participating in a broader array of cooperative projects.

If this hypothesis is correct, it might explain not only the origins of our general capacity for normative judgment and motivation, but also the widespread tendency for social rules or norms historically to emphasize such things as group identity, loyalty and cohesion, and to focus largely on the regulation of violence and sex; and it might help to explain widespread dispositions toward social conformity, concern with reputation and social standing, tendencies for group-wise scorning or punishment of the disloyal, and the power of emotions such as resentment, guilt and shame

In the final phase, this sort of “proto-morality”of norms and reactive emotions would then be supplemented over thousands of years with various paths of cultural evolution, leading to the development and fleshing out of the much more sophisticated systems of moral beliefs, practices and institutions with which we are familiar, from the earliest historical examples right up to our present moral cultures 

we cannot know about causation or the soul. The only thing we can know about morals is that we get pleasure from the thought of some things and pain from the thought of others. Since the idea of morality implies something universal, there must be some sentiment of sympathy (Hume)

Hume thought we could get conventional moral conclusions from these moral sentiments, which nature has fortunately given us. He was also skeptical about any attempt to derive conclusions containing ‘ought’ from premises containing only ‘is’,