Christianity, the most successful religion on Earth, has several characteristics worth highlighting as what may be the closest real-world example of my model for an ideal society.
Like Judaism, on which it is founded, there are only a handful of rules that individuals need to remember for minimum functioning of the society: the Ten Commandments. Christianity includes one more rule that encapsulates the others in case they are forgotten: Love your neighbor (including the disadvantaged) as yourself. This last rule is the essence of altruism, which translates into the maximizing of every individual’s happiness and longevity.
Christianity also has a mandate for growth, enabling its expansion to include most of the human population. By defining all of humanity as its “family” (most favored group), it assumes that it will eventually include the entire species. Based on its Judaic tradition, it mandates that the population will continue to increase (maximizing population and, in a world not constrained by resources, longevity of the species).
Earth’s population growth must eventually end, and Christianity even forecasts how this might happen (one might even say that it programs its members to fulfill the prediction). Simply put: the entire world becomes unified, a fight breaks out over sacred territory, and then a chosen few escape into heaven. One pretty realistic scenario paralleling this narrative involves a globally integrated society fighting over diminishing resources and launching a small breeding group into space to survive the ensuing population crash.