I've come across some interesting articles in the past several weeks about recent research on understanding how creativity correlates to processes in the brain. The work was done by the group of Rex Jung at the University of New Mexico using structural magnetic resonance imaging techniques. I read about this work in a New Scientist article, but a copy of the original paper is online: "Neuroanatomy of Creatvity", Human Brain Mapping 31:398-409. Jung's work was also covered in a recent New York Times article, as well as a Psychology Today blog article, which connects his work to other neuroimaging research on creativity.
A few things resonated with me from the research described in these articles. Based on cogitations about my own mental processes, I've developed a strong intuition that there are two broad distinct modes of thinking that are largely independent and complementary, which one could characterize as intelligence and creativity. By intelligence I mean mental processes centered around the ability to recall factual knowledge and make straightforward inductions and deductions using this knowledge. Creativity, on the other hand, has always seemed to me to be an entirely different mode of mental processing, that involves the nontrivial synthesis of knowledge and observations in order to solve problems that may have never been posed before, and leading to solutions/ideas/insight that are not linear extrapolations of existing knowledge. My intuition is that the flourishing of one of these modes of thought in an individual tends to result in a diminishing of the other mode, and that it is a rare individual that has highly exceptional abilities for both modes of thinking (these people I would say have the potential to achieve "genius" status).
Based on the research described in these articles, there appears to be evidence supporting this basic notion that intelligence and creativity are largely uncorrelated. In the Psychology Today blog article, John Allen considers the implications of this from an evolutionary standpoint: "This leaves open the possibility that creativity, in evolutionary terms, is not simply an emergent property of increased intelligence." He also points out the important observation that these types of studies, that seek a material, neuroanatomical basis of creativity are necessary to eventually make a genetic correlation to creativity.
Another thing I found interesting were their observations of the structure of "grey matter" versus "white matter" in creative individuals. Grey matter is tissue made up of neurons and is traditionally associated with raw thinking power, while white matter is tissue surrounding or connecting neutrons. What they found was that creative people tended to have thinner white matter tissue, which has the effect of slowing down the transmission of information. The implication is that creative thinking tends to proceed more slowly in the brain. From the New York Times article: "This slowdown in the left frontal cortex, a region where emotional and cognitive abilities are integrated, Dr. Jung suggested, 'might allow for the linkage of more disparate ideas, more novelty and more creativity.'" That's pretty interesting.