A person’s moral life is deeply complex and mirrored in the diverse sets of moral associations, responses, and dispositions a person inherits and develops in a lifetime. The philosophical and biological meanings of dispositions are discussed, suggesting that they act as a frame guiding experience and action. Using triune ethics meta-theory, we discuss the dynamism of development, ongoing interaction of nature and nurture through epigenetic processes, and the interaction of brain maturation and caregiving in light of evolution, specifically, the evolved developmental niche. Each individual has capacities to help themselves and to self-author their moral habits, no matter what happened in childhood. Education, social environment, and personal and social practices influence personal and social moral life, including the difficult and communal task of understanding, defining and developing human well-being.