from a young one. a lack of concern for others aka selfishness. some people are selfish with abusive backgrounds, some people are selfish without abusive backgrounds. some people are selfish with crappy genetics, some aren't. personal responsibility is another factor in the equation that is easily overlooked these days. it may be much more difficult for some people to treat others well considering their horrible backgrounds and genetics but it doesn't give them a pass. they are still responsible for their actions unless they are mentally/psychologically disabled. sometimes when we give ourselves over to certain behaviors (rage, drugs, alcohol, etc.) for long enough we become enslaved to them and have lost any sense of control over them. then, one is really in trouble. those weaknesses can be inherited too like with alcoholism but they are a part and not the whole cause for immoral behavior. yes, i think there are immoral behaviors...murder, stealing, and whatnot.

just my 2 cents.