The prevalence of joined senses
Synesthesia is a neurological trait where the stimulation of one sense automatically triggers an experience in another. For a person with synesthesia, or a synesthete, a sound might have a color, a letter might have a gender, or a word might have a taste. Research conducted at the University of Sussex by psychologists like Professors Julia Simner and Jamie Ward has been central to understanding this phenomenon. Their work established that synesthesia is more common than previously thought, affecting at least 4.4% of the population. This figure is significantly higher than earlier estimates, which sometimes placed the prevalence as low as one in 25,000.
There are over 60 documented types of synesthesia. One of the most common forms is grapheme-color synesthesia, where individuals associate specific colors with letters and numbers. Another frequent type is chromesthesia, where sounds evoke an experience of color. Less common variations include lexical-gustatory synesthesia, where words have distinct tastes. The trait often runs in families, pointing to a genetic component, and the specific sensory associations—like 'A' being red—remain remarkably consistent throughout a person's life. Brain imaging studies show that synesthetes have different patterns of neural connectivity, with increased cross-activation between sensory regions of the brain.
A link to creativity
The University of Sussex is also where scientists have investigated the long-suspected link between synesthesia and creativity. One study focusing on art students revealed a prevalence of grapheme-color synesthesia at 7%, compared to just 2% in a control group. Other research found that musicians have 4.4 times higher odds of having synesthesia compared to non-musicians. Specifically, the odds for grapheme-color synesthesia were 7.7 times higher in musicians.
This connection is a modern observation. Many well-known artists, writers, and musicians are reported synesthetes. The painter Wassily Kandinsky spoke of how colors created sounds for him. Novelist Vladimir Nabokov, who had grapheme-color synesthesia, described the letter 'g' as a "rubbery tone". Contemporary musicians like Billie Eilish, Pharrell Williams, and Billy Joel also report using their synesthetic experiences in their creative process. The hypothesis is that the neural pathways in synesthetes may facilitate the kind of abstract and metaphorical thinking that is fundamental to artistic creation. Studies show synesthetes can have advantages in some cognitive areas, like memory, which may also contribute to their creative output.