What you are saying is that they can't delay gratification and they are highly impulsive although I can think of many psychopaths who are very succesfull and they can exhibit many traits of a normal person. There was another study which showed that psychopaths kept playing again and again, a particular video-game even though they knew they were going to lose. This might show persistence and the inability to accept defeat. To have an impaired prefrontal cortex it might show a deficit in self-control and analytical reasoning or metacognition. That could explain why they might act impulsive and choose the short-term outcome.