Another factor here is the nature of the "group", mainly how they make a living. As Geez implies, this is an optimization problem. Ants and bison have arrived at different solutions, and in fact the Inuit and Polynesians and Belgians have arrived at three different solutions too, because even though they're physically the same, they're in three different environments. On the other hand, ants and bison living in the "same" environment are actually living in very different environments, because they're not in the same niche. Meanwhile, as a species evolves over many zillions of long and boring years, Geez's "reward matrix" will change, and what was optimal a million years back will begin to look a bit silly. We seem to have reached that stage here in Cambridge. I don't know about Wisconsin.
This "pressure against being evil" is not necessarily a survival trait. Sometimes it is, and sometimes not -- and even when it is, it'll be so to varying degrees depending on circumstances. Also, you're thrashing away at nature with an arbitrary, local, and vertiginously temporary definition of "evil".
dizzy's question could be rephrased (broadly) as "How come Homo sapiens isn't well suited to living in Cincinnati?" The answer is this: He hasn't been there very long, and by the time he starts getting used to it, Cincinnati will have changed beyond recognition.
Evolution is frustrating. That is why I choose not to evolve.
Halcyon&on: But Survivor was an artificial environment, and a very small sample as well. I don't think it creates any problems for the rest of what you're saying. Furthermore, that guy "survived" by completely eliminating his social group. In the long run, eliminating all of your breeding partners probably isn't the best evolutionary strategy...) In fact, the win-by-annihilation-and-thereby-lose approach is pretty much what you're describing with the Amazon basin. It's a mentality we probably picked up back when we couldn't actually annihilate everything, so the "-thereby-lose" part didn't kick in. Back then it was useful, and it only applied to things outside the group anyway: Other groups, wolves, etc.