@AlexStone I would hypothesize along the same lines, i.e. a part of it indeed seems to be nature rather than nurture. It's weird that this subject doesn't appear to have been studied more extensively, especially given the potential impact it could have. I guess this is where e.g. virtual reality + fMRI and similar techniques could be used to establish more empirical conclusions.

@Steven Jeuris: agreed. The reason the question is so broadly formulated is that this is also an attempt to perhaps redefine it or narrow it down, but I need some input from actual (cognitive) scientists to do it appropriately - i.e. what specific questions have been researched or could be researched, what is out of current technology's ken etc. I would be more than happy to receive partial answers or pointers that would help me to ask more specific subquestions. Another problem is that SE network doesn't have a site for such multidisciplinary questions (which I believe are important).

But doesn't "greater good" in this sense appear too transcendental to be explained by purely evolutionary goals of an individual? How could e.g. concerns for some notion of a better future society be explained purely evolutionary (consider an individual without family, friends, children, or loved ones)? Sure, evolution has shaped and enabled such behavior, but that doesn't really answer much - e.g. evolution has also enabled me to use my arms and eyes to prepare food, but that says little about the nature of hunger. :) And it's this biology-behavior relation that I'd like to know more about.

Thank you for your answer. However, I don't think altruism is a particularly good example of meaning seeking in the context of this question; group-based evolutionary arguments don't seem to suffice either. Meaning seeking can be highly (purely?) individual thing (suicides out of honor, risking social exclusion to stand for your values etc.). All this considered, a more suitable explanation seems to be that we can indeed override our evolutionary/biological drives with custom interpretations of the world. The question then is how do these custom interpretaions reflect on a biomolecular level.