as I said to dasil003, it's not really about behaviour, it's about genes. to reply to your post: we have a better understanding of the world compared to the other animals so maybe it simply happened that at a given time we understood that cooperation allows you to gain an unfair advantage vs single individuals and so on (in some way you need to keep that cooperation going).

my point is that it seems to me that exploitation of weaknesses is the central theme of evolution and it doesn't mix well with fairness. then again, I don't study biology so take my words with a grain of salt.