title: The effect of iconicity of visual displays on statistical reasoning: evidence in favor of the null hypothesis.
abstract: Knowing which properties of visual displays facilitate statistical reasoning bears practical and theoretical implications. Therefore, we studied the effect of one property of visual diplays - iconicity (i.e., the resemblance of a visual sign to its referent) - on Bayesian reasoning. Two main accounts of statistical reasoning predict different effect of iconicity on Bayesian reasoning. The ecological-rationality account predicts a positive iconicity effect, because more highly iconic signs resemble more individuated objects, which tap better into an evolutionary-designed frequency-coding mechanism that, in turn, facilitates Bayesian reasoning. The nested-sets account predicts a null iconicity effect, because iconicity does not affect the salience of a nested-sets structure-the factor facilitating Bayesian reasoning processed by a general reasoning mechanism. In two well-powered experiments (N = 577), we found no support for a positive iconicity effect across different iconicity levels that were manipulated in different visual displays (meta-analytical overall effect: log OR = -0.13, 95% CI [-0.53, 0.28]). A Bayes factor analysis provided strong evidence in favor of the null hypothesis-the null iconicity effect. Thus, these findings corroborate the nested-sets rather than the ecological-rationality account of statistical reasoning.
authors.affiliation: Medical Decision Making and Informatics Research Group, School of Medicine, King's College London, Capital House, 7th floor, 42 Weston Street, SE1 3QD, London, UK, miroslav.sirota@kcl.ac.uk.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Sirota
authors.forename: Lenka
authors.initials: L
authors.lastname: Kostovičová
authors.forename: Marie
authors.initials: M
authors.lastname: Juanchich
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001499:Bayes Theorem; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology*; D013850:Thinking / Q000502:physiology*; D055815:Young Adult