You'll find that a lot of predators (serial killers, sexual predators) were abused as children. Poverty seems to be a factor, but that alone doesn't usually cause such a lack of remorse later in life. Something like extreme affluenza seems to cause it in some people, too. That's probably more about having control over someone else and being used to get your way, even being rewarded for it.

Wiki's got lots of information on the topic if you don't mind seeing how people can turn into animals.