ABSTRACT
This chapter asks some big questions. Why does synesthesia exist? Does it have any advantages? Did it evolve for a particular reason? As such, the discussion will focus on the developmental variety of synesthesia that is known to have a genetic component. Synesthesia is de®ned in terms of unusual sensory experiences, and I have argued that this has its roots in the kind of multisensory perception that we all continually engage in. Although this is fascinating in its own right, perhaps it is a red herring in terms of the bigger picture. For instance, one widely publicized claim is that synesthesia could exist to permit human creativity. Under this account, the actual sensory experiences are a byproduct ± a colorful sideshow ± of synesthesia's real purpose in life. I will cast a critical eye over this and other claims.
