The history of Synesthesia starts with early research in the 19th century
The history of synesthesia research dates back to the first scientific reports that derive from George Sachs in the year 1812. In his dissertation he describes his own synesthetic perceptions. Sir Francis Galton, the cousin of Charles Darwin, described some synesthetes in his work Colour associations. The interest and attention on this field raised and some publications followed. The US-scientist Mary Calkins introduced the term synesthesia or synaesthesia at the end of 19ths century.
Around 1930 the behaviorism gained importance in psychological science: Learning and behavior were reduced on interactions with external stimuli. In this period many experiments in conditioning where conducted. It was assumed that internal feelings and thoughts are not measurable. Therefore synesthesia did not fit into the scientific approaches of this time. It was forgotten for several decades.
All “acid junkies” and “pot heads”?
The lack of information about synesthesia lead to the circumstance that synaesthetes were classified long time as “ill”, as „people with great fantasy”, or as „Acid-Junkies” or „Pot-Heads”. Despite the skepticism of the scientific community, Richard E. Cytowic was one of the first who began to dedicate with synesthesia at the end of the last millennium. He he coincidentally met a man that tasted shapes and started to investigate. Other scientists followed and synesthesia gained more and more on importance and interest.
Since the beginning of this millenia synesthesia research became its own branch in psychology. In the beginning conclusions mainly were drawn by interviews with synesthetes, Nowadays there is a lot of empirical research. information is gained by experiments with synesthetes and non-synaesthetes, statistical analysis and not due to statements of some single synaesthetes.
Synesthesia is real. The current research is about the mechanism of the brain and the benefits of synesthesia. The more we know, the less we understand. We hope for exciting years of scientific insights and explorations.
For more about the history of synesthesia read Jörg Jewanskis chapter in the Oxford handbook of synesthesia.