They selfishly take what they want and do as they please

Psychopaths are social predators who charm, manipulate and ruthlessly plow their way through life, leaving a broad trail of broken hearts, shattered expectations and empty wallets. Completely lacking in conscience and feelings for others, they selfishly take what they want and do as they please, violating social norms and expectations without the slightest sense of guilt or regret.

– Robert D. Hare, Ph.D., from the beginning of his book about psychopaths, Without Conscience