Is it normal to be abusive? To answer that question, we should observe man's actions. By his behavior, we learn his nature. If we look, we see men abusing, robbing, lying to, raping, and murdering each other. I think the obvious conclusion is that men are naturally selfish, evil creatures.
Thomas Hobbes said in Leviathan that, "The condition of Man...is a condition of Warre of every one against every one."
"Man is least himself when he talks in his own person. Give him a mask, and he will tell you the truth." -Oscar Wilde