So I saw these posts of a kind that I dislike where people completely misuse science in pursuit of their argument and wrote most of a big rant about how terrible I think that is. But then I was like "Wait, it's like 3:30 AM, you should just save what you've written, go to bed, and decide if it's worth posting in the morning." But then I refreshed the thread and saw that this nonsense was still going on and getting more ridiculous and then I realized that no, there would be no sleep. Sorry to go off on you like this, because it's not like this is the first time I've seen this kind of thing go on; in the future I'll just link to this post when I see it happening and start getting angry.
"Evolution" does not have a direct effect on an individual's temperament, personality, and above all personal choice and actions. An individual's behavior is not somehow "optimized" for superior survival and reproduction, and everything that one does is absolutely not directly related to survival and reproduction, and this is especially the case with humans, who have all this funky culture-y stuff sitting on top of our genetic behaviors and causing us to do damn strange things from time to time. One can definitely conjecture about why, for example, the drive to create art might be advantageous for the human species as a whole, but trying to link that to the fact that you felt like you wanted to doodle in class today is pointless. You do not doodle in class because this is what evolution has built you to do anymore than you doodle in class because cosmic events caused the earth to be formed in such a way as to support the development of intelligent life, boring lectures and, eventually, pencils. I mean, yes, there is some truth to that statement; you certainly would not be doodling if some teensy self-replicating thing had not appeared out of the primordial stew billions of years ago. Nevertheless, an understanding of the descent of life as we know it does not really do much to enrich one's appreciations behind the specific causes of your behavior at that time.
All that aside, it's almost always a bad idea to bring up scientific studies in this kind of context for many reasons:
1) It's inevitably Not that Simple; the study of altruism and its potential evolutionary purpose is a lively field, full of deliciously passive-aggressive research papers about how theory X is wrong but my theory Y over here is totally legit, for example. It's not like "Science has found the answer!!!" here.
2) Our understanding of what makes animals, human or otherwise, tick beyond the very most basic level, is still extremely primitive, and most of it is likely wrong.
3) Experiments that attempt to study these sorts of things are especially prone to methodological problems and creative results interpretation, often because questions about human behavior and evolution have a tendency to be experimentally intractable.
4) Human behavior is not well-represented by that of any other species. Our species appears to rely on culture to guide our behavior far more than any other species on earth. Attempting to draw conclusions about human behavior based on animal behavior is therefore a very dicey business.
But most especially,
5) Science is not a prescriptive tool. It has no ethical dimension; it deals, as best it can, in facts and laws. So when you say, "science says this, therefore it is GOOD/BAD that I do X," you are almost always doing it wrong. Science can only say, "X happens," and if we're super-lucky, "X happens because of Y," or even, "if X happens, then Y will happen." But that does not make X happening a desirable or undesirable thing. Say that there is evolutionary pressure towards people being self-interested. Does that mean that it is good to be self-interested? I don't know! Certainly the statement "there is evolutionary pressure towards being self-interested" doesn't say that. When you say that science suggests an underlying cause behind something that you or someone else does, if you then go on to state that this is somehow right or wrong, please understand that you are making a leap that the facts do not support. You are operating under the unstated assumption that what is in accordance with natural selection is automatically right/only to be expected/"just the way things are," and that assumption can be debated and attacked in its own right. And we can come to that point only if we accept the further assumption that evolution has any kind of relevant bearing on the day-to-day lives of individuals (not very likely, in my opinion).
I apologize for going off on a huge snarky tangent over a pretty minor comment or two, but whenever I see people trying to bring up SCIENCE!!! in these sorts of debates it almost invariably gives me the sads. If you're feeling the itch to pull a "but SCIENCE!! says!" in a debate, please take a moment to really consider what SCIENCE!! actually says, and whether you are actually coloring scientific fact with your own interpretations and value judgments, which may or may not be shared by the other people in the debate and can certainly be argued over. And if you ever feel the need to state as a fact some sweeping generalization about how people behave that is in fact hotly debated among scientists and only tangentially related to your claim without providing any sort of citations or explicating your actual argument, please envision your favorite scientist (we'll say Einstein if you're at a loss) drifting out of your computer screen and smacking you with a rolled-up copy of Nature. And then don't make the post.
