The most prosperous people usually have the lowest levels of violence, see Pinker's works. Contempt for life springs from one of three things:
1) desperate conditions, including addiction or extreme poverty
2) a sense of entitlement, entitlement to "choice" for instance
3) the illusion that a collective identity or society is real, as in Hegelianism where races, classes, ethnicities, nations, etc. are almost thought of as organisms with rights of their own that supersede those of the individual.