The effect of iconicity of visual displays on statistical reasoning: evidence in favor of the null hypothesis

Psychon Bull Rev. 2014 Aug;21(4):961-8. doi: 10.3758/s13423-013-0555-4.

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.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Bayes Theorem*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pattern Recognition, Visual / physiology*
  • Thinking / physiology*
  • Young Adult