As someone who has been raised in a non-violent environment, I am often surprised how people in some circles easily resort to vengeance and violence while a conciliatory attitude could have resolved "issues" quickly and efficiently. There is certainly a good deal of learned behavior that determines whether you are of a conflicting or conciliatory type, and this learning comes from example, in the family, among peers and in society. Society is important (say, compare Scandinavia to the Balkans) but there are also striking differences within societies. That is where parents may come in.
Ruby Henry studies how the use of retaliation is transmitted to children, first using a model of education effort by parents, and then using UK National Childhood Development Survey. The theoretical prediction is confirmed that high-cognitive parents are better able to transmit their values and override the peer culture, as long as the parents are retaliators. Indeed, if a child is told to retaliate and meet a forgiver, he wins and his values are reinforced. If he is a forgiver and meets a retaliator, he looses and is upset by the teachings of his parents. It the long run, this means that humankind will settle on a retaliating culture. But I do not think this is what we observe. In fact, there are less wars, people abide more to contracts and, I think, respect more the rule of law over time. Correct me if I am wrong.