title: Synaesthesia: the prevalence of atypical cross-modal experiences.
abstract: Sensory and cognitive mechanisms allow stimuli to be perceived with properties relating to sight, sound, touch, etc, and ensure, for example, that visual properties are perceived as visual experiences, rather than sounds, tastes, smells, etc. Theories of normal development can be informed by cases where this modularity breaks down, in a condition known as synaesthesia. Conventional wisdom has held that this occurs extremely rarely (0.05% of births) and affects women more than men. Here we present the first test of synaesthesia prevalence with sampling that does not rely on self-referral, and which uses objective tests to establish genuineness. We show that (a) the prevalence of synaesthesia is 88 times higher than previously assumed, (b) the most common variant is coloured days, (c) the most studied variant (grapheme-colour synaesthesia)--previously believed most common--is prevalent at 1%, and (d) there is no strong asymmetry in the distribution of synaesthesia across the sexes. Hence, we suggest that female biases reported earlier likely arose from (or were exaggerated by) sex differences in self-disclosure.
authors.affiliation: Psychology, University of Edinburgh, Scotland, UK. j.simner@ed.ac.uk
authors.forename: Julia
authors.initials: J
authors.lastname: Simner
authors.forename: Catherine
authors.initials: C
authors.lastname: Mulvenna
authors.forename: Noam
authors.initials: N
authors.lastname: Sagiv
authors.forename: Elias
authors.initials: E
authors.lastname: Tsakanikos
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Witherby
authors.forename: Christine
authors.initials: C
authors.lastname: Fraser
authors.forename: Kirsten
authors.initials: K
authors.lastname: Scott
authors.forename: Jamie
authors.initials: J
authors.lastname: Ward
mesh_terms: D000328:Adult; D016009:Chi-Square Distribution; D002648:Child; D003118:Color Perception; D003463:Cues; D005260:Female; D006801:Humans; D008297:Male; D009146:Music; D010468:Perceptual Disorders / Q000175:diagnosis / Q000523:psychology*; D015995:Prevalence; D011932:Reading; D012650:Self Disclosure; D012737:Sex Factors; D011795:Surveys and Questionnaires