Synesthesia and evolution

We've posted many times about synesthsia, a fascinating and bizarre neurological condition in which two ore more senses are linked so that someone, for example, might "taste" sounds or "hear" colors. New research is exploring whether synesthesia, which appears to be a heritable physical condition, has survived evolutionarily because it's beneficial. According to the UC San Diego scientists, "ninety-five to ninety-nine percent of synesthetes love their synesthesia and say it enhances their lives." Advanced brain scans are enabling researchers to better see the increased connections between sensory brain regions and learn more about the neural condition. From National Geographic:

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The study authors think it's possible such a strange phenomenon has survived in an evolutionary sense because it offers people certain benefits to creative thinking.

Such studies could also help test an idea proposed by some scientists that all humans have the neural mechanism for synesthesia but it's suppressed for some reason…

…Synesthesia is about seven times more common in artists, poets, and novelists than in the rest of the population, and some scientists have hypothesized that synesthetes are better at linking unrelated ideas.

"Why Does Evolution Allow Some People to Taste Words?"