Okay, this topic inspired me to do a bit of word vomiting. The tl;dr is that I acknowledge the selfish evolutionary origins of my own moral intuitions, and I have found that following these intuitions generally supports my emotional well-being so I do so without really worrying about where they come from.

I used to find my outlook on morality and interaction in general plagued by a vague sort of biological determinism and psychological egoism. The hypothesis I operated on was that morality is rooted in psychological mechanisms for cooperation, exchange, and inclusion in groups, with the ultimate purpose of increasing ones reproductive fitness. In simple terms, it sometimes benefits us to act such that those around us will trust us, support us, and generally want us around, so we have natural tendencies to do so. I supported (and still support) this belief with bits of theories and hypotheses such as reciprocal altruism in animals and cheater detection mechanisms in the human psyche.

It bothered me a lot. I did not believe that truly selfless acts were possible, and I found myself wondering whether I shouldn't just acknowledge that selfish biological drives are the sole sources of my motivation to do anything and factor this in to my everyday decision making processes.

Eventually my point of view changed a bit. A good deal of introspection and experimentation brought me to the conclusion that if my understanding of human behavior and moral motivation were true, this would actually justify my own desire to uphold moral principles. Simply put, I found that acting in accordance with intuitive moral principles gave me a sense of inner peace and disregarding such principles made me feel guilty.

I am not very well educated philosophically, but a combination of a couple introductory philosophy classes and a lot of SEP articles and discussions on Reddit have helped me clarify what my intuitive moral positions are and how they can apply to my behavior. These days I don't really care why I feel that I shouldn't harm other people. I have the good fortune of living in a place and time in which I appear to have a decent chance at success in life without it being necessary to engage in many physical or even verbal conflicts , to disregard the well-being of my family and friends, or to really fuck anyone over in any sense. If it had been my experience that violence, neglect, dishonesty, etc. were necessary for me to get where I want, be happy, or avoid discomfort, I would be pretty conflicted. Fortunately I rarely have to choose between doing what feels right and getting my needs met, so I don't really worry about it too much.