The Brain: There are two major parts of the brain, the frontal lobes and the cerebellum. The frontal lobes control most of the decision making and planning, as well as higher levels of processing. In other words, people with high IQs usually have a large frontal lobe, and people who have low IQs have a small frontal lobe. It is often argued that all of the research shows that the frontal lobes are a good thing. This is true, however, it also appears that some areas of the brain have very little function in terms of reasoning, while others are very effective in some aspects of decision making. The cerebellum is a very small area of the brain, and is sometimes called the "thinking brain." However, the cerebellum also has a large effect on processing information, which is why a lot of studies show that people who have a high IQ tend to do well in math and science. There are several theories about how the cerebellum functions, and the ones that appear to be most accurate are the "Wagner's gyrations" model. This theory posits that as you move from one position to the other in a game of musical chairs, the cerebellum slows and speeds up, creating an "inner gyratory." These inner gyrations make it difficult to predict the next move, but they can be used to predict the previous move.