I sense that selfishness (or lack there of) has quite a bit more to do nurture, rather than nature.
Where Aspergers (characterized with difficulties in empathizing with others) is a factor, Aspergers individuals are often very receptive towards learning (from thoughtful family, friends, counselors, teachers) to reciprocate others favors, consider other people needing help, and exercising manners and courtesies as second-nature.
Personally, I feel fortunate to understand that I can benefit from help, and relationships with thoughtful neuro-typical, and Aspergers people alike; because of an understanding that assistance is mutual; that is help can only work as a two (or more) way street.
On larger issues, I've found the Internet as 'a godsend of sorts' to assist on social, political, and even environmental agendas both near and far. Even through donating to charities; I always strive to understand, "what more can be done to make a bigger difference?"
The wisdom that a person (or persons) are either part of a problem, or part of a solution is a strong sentiment!
The "fly in the ointment" (to supplement Internet resources) are difficulties with face to face interaction; which ironically can stem out of concerns of....a selfish world at large!