>> well, there's two components of that. certainly our ability to operate executive control and make choices of purr sufing goals like employment and the long-term relationship over drugs of abuse or overeating is very essential. but very new research is finding that there's individual differences in how quickly we learn to associate cues with reward from food or drugs and the people who rapidly learn these cues for reward, they're the ones that get sucked into the habit much more than other people. so, there are genetic differences that have an influence on this. so, willpower, putting it very concisely, some people don't have to bring much willpower to the table wheresas other people have to bring a great deal. >> thank you, shed some interesting insights to that, appreciate that. a check of your top stories minutes away. but still ahead, doogie howard m.d. versus sanjay gupta,