An academic trying to simulate a human brain has a massive super computer devoted to the task of thinking, while an AI programmer for a video game is instead working with a small percentage of processor power. The majority of the computing power in games is instead going towards depicting graphics, sound, physics, and cow bell type things. For example, technically the AI in Halo 3 is less sophisticated than in Halo 2 because most of the processor has to be devoted to graphics. A giant, open world game will inherently have stupider AI because there just isn’t enough power to go around. So the art of video game AI is in making a player think that they’re interacting with something more sophisticated than it really is.
via popmatters.com