In this web video, Stanford Neurology Professor Robert Sapolsky discusses how dopamine affects human behavior: the anticipation of a particular reward is more important than actually getting the reward. He singles out Las Vegas as a place where human beings are manipulated to believe they can win money, even though they have a slim chance of doing so. It is a great explanation about dopamine and how, why, and when our levels rise. Casinos and lotteries design their experience to blatantly exploit these traits.