Kindness is like gene game theory with more math (or, I am high and I listen to a lot of National Public Radio)
If natural selection is an indifferent process where traits that cause reproductive success are selected for and traits that reduce reproductive success are selected against, then how can a trait that doesn't on face increase reproductive advantage exist? Put another way, how can natural selection account for a behaviour that makes us less likely to survive?
Selflessness/altruism is a great example of such a behaviour. We know animals compromise their own well-being (and by extension reduce their own reproductive success) to benefit other animals. It's inconsistent with natural selection, but we know it happens. So, I guess life isn't just a cold recursive (not too sure I'm using this word correctly) process of passing on traits that are beneficial in the game of passing on traits. LOL JK. It turns out- it sooo is!
rB > C. This means genes for altruism evolve if the benefit (B) of an action exceeds the cost (C) to the individual once relatedness (r) is accounted for (i.e., even if it looks selfless it is not, because your genes did the math and you're altruistic act is really aimed at increasing the reproductive success of your genetic relatives.)
So remember, kindness doesn't exist. Stay frosty.
NPR: http://www.radiolab.org/2010/dec/14/equation-good/
Also, Plants Are Dickheads Too: www.sciencedaily.com/releases/2013/02/130201132334.htm