>>10
bug in natural selection.
Natural selection has no purpose (same with the laws of physics).
Don't think natural selection could come up with a clear ``program'' to prolong the existence of one's (2-sex) species without modifying the reward system in some crude way (as we are now)
in fact it's just an addiction.
Everything is just an addiction: food (specific tastes), desire to continue to exist, sex, music (and other types of entertainment), desire to not experience pain and so on. It's all in your reward system. If there would be no motivation to do something, an organism wouldn't do that thing. ``Addiction'' is a pointless word in this case. Without a reward/motivational system, you would just be a general intelligence which is not likely to do anything or be able to make any decisions (I'm too lazy to go look up the papers on studies done on people that have damaged reward systems, but they are fairly incapable of making decisions, they could see the consequences of their actions, but have no reason to do one action or another). No ``addiction'' would lead to no life/survival at all.
Pleasure is a qualia we associate with certain neural firings, but the purpose is merely to increase the likelyhood of certain behavior. Humans' general intelligence does lead to us easily finding ways to exploit the process to merely give us pleasure without having to do the behavior that led to the selection of those genes. We're just executing an adaptation and the adaptation has no ``purpose'', despite that on average (when the adaptation appeared) that adaptation may lead to certain behavior that selected for it in the first place. Evolution is not a directed process. Also,
http://lesswrong.com/lw/l0/adaptationexecuters_not_fitnessmaximizers/