Selfish or Altruistic?

When reading Richard Dawkins, "The Selfish Gene", I have discovered that I read in a different tone than when I read a novel. It is different to read science because one tends to have to pay much more attention to everything you go through, you cant afford to doze of because you than all that you have read because one must understand things in a chain to be able to get them straight. In novels and other books, you can sometimes doze off a few paragraphs and then get once more involved and you still understand everything that is going on. In "Slaughter House Five", for example it isn't as bad to doze off. plus the experiences told in the novel usually make it easier for you to doze of because it leads you to think about your own experiences or you get a point of view or perspective in a certain topic so you doze off. In this book it is even less worse since it doesn't have a straight time line so you can go back and forth with the thoughts and you wont really get lost. "The Selfish Gene" has also gotten me involved in a topic that i actually enjoy and would like to learn about.
In this book the author says he will discuss why humans are selfish and how this characteristic has gone from generation to generation. He says its not just a human trait but many animals have it and it is actually indispensable for evolution and survival. However he also talks about altruism and how it may help for survival but that there will never be a completely altruistic group since selfishness always develops and takes over. It also talks about individual selection and how one may survive and then transmit to others that characteristic. He talks about selfishness being necessary for survival and a natural thing in creatures.
One thing that actually impressed me was the fact that he wasn't going to talk about nature vs nurture since he didn't really consider it that important. I , on the contrary, believe that that is very important because society really can transform you in some ways but that there are other things that you inevitably inherited and there is nothing you can do about it. Last year, in PDR, we actually did a debate on this subject and we concluded that both are very important on the development of a person. So it actually surprised me when the author specified that this would be one of the topics which he would not discuss.