On that note, I just came across a book by Matt Ridley, about this very revelation that helping others can benefit you. This guy who wrote The Rational Optimist, which is a very interesting but I think misleading book. If you do pick it up make sure to read the prologue which I found more insightful than the rest of the book, and a bit contradictory to the rest of the book. Anyways, check out the description of the new book, (I mean old book, on audible it has a 2014 date on amazon it says 1998, I guess it's new to the audio book world)
The Origins of Virtue: Human Instincts and the Evolution of Cooperation
If, as Darwin suggests, evolution relentlessly encourages the survival of the fittest, why are humans compelled to live in cooperative, complex societies? In this fascinating examination of the roots of human trust and virtue, a zoologist and former American editor of The Economist reveals the results of recent studies that suggest that self-interest and mutual aid are not at all incompatible. In fact, he points out, our cooperative instincts may have evolved as part of mankind's natural selfish behaviour - by exchanging favours we can benefit ourselves as well as others.