The subject of synesthesia is making the media rounds again. 60 Minutes II did a story on it recently and an article appeared in the Washington Post this week. I was fascinated by The Man Who Tasted Shapes, mainly for its theory that synesthesia is a primitive limbic brain function, perhaps a clue or at least a vestige of man’s ascent into intelligence and emotional experience. After the NY Times Book Review printed a negative review of the book in 1993, its author, Richard E. Cytowic MD, posted a scathing response on Usenet. I had an email exchange with him following that, which consisted of me using big words to tell him how cool I thought his book was and how wrong the reviewer was, and him responding in a suitably nice manner. Since then, and it has been almost 10 years, scientists have not reached an agreement on what causes the phenomenon or even how many people have it, but they do agree that it exists and can be inherited. Perhaps more than one theory is correct, as I have heard that you can acquire and lose synesthesia as a result of brain disorders. I have always wondered how many people do not realize that they have some form of synesthesia until they learn about what it is, a situation the author of the Washington Post article finds herself in.