Related Experiment Video
Updated: May 9, 2026

08:12
A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments
Published on: March 1, 2022
A quantum geometric model of similarity
Emmanuel M Pothos1, Jerome R Busemeyer, Jennifer S Trueblood
1Department of Psychology, City University, London, EC1V 0HB, London, UK. emmanuel.pothos.1@city.ac.uk
Psychological Review
|August 7, 2013
Summary
Quantum theory offers a novel approach to understanding similarity, explaining Tversky
Area of Science:
- Cognitive Science
- Mathematical Psychology
- Quantum Theory
Background:
- Tversky's (1977) seminal work challenged fundamental assumptions of geometric similarity models.
- Similarity judgments were shown to violate symmetry, triangle inequality, and exhibit context effects.
- Existing geometric models fail to fully account for these observed psychological phenomena.
Purpose of the Study:
- To explore quantum theory as a generalized geometric framework for modeling similarity.
- To demonstrate how quantum probability can address Tversky's findings on asymmetry and context effects.
- To investigate the implications of a quantum approach for representation theory.
Main Methods:
- Modeling psychological similarity using principles of quantum probability.
- Analyzing how quantum probability accounts for order effects (asymmetries) and context-dependent diagnosticity.
- Relating violations of symmetry and triangle inequality to quantum probability's context-dependent nature.
Main Results:
- Quantum probability naturally explains order effects, addressing observed asymmetries in similarity judgments.
- Context-dependent properties of quantum probability account for violations of the triangle inequality.
- The diagnosticity effect in similarity is explained through the lens of quantum probability.
Conclusions:
- Quantum theory provides a powerful and generalized geometric approach to modeling psychological similarity.
- This quantum framework successfully addresses key findings that challenged traditional geometric models.
- The study highlights the potential of quantum probability for advancing representation theory.
Related Concept Videos
The Quantum-Mechanical Model of an Atom
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra. Schrödinger...
Modeling and Similitude
Scaled modeling is a fundamental technique in engineering, enabling the study of large and complex systems by creating smaller, manageable replicas that recreate critical characteristics of the original. In hydrology and civil infrastructure, for example, scaled models of dams help analyze water flow, turbulence, and pressure. This method allows for accurate predictions of real-world behavior within a controlled environment, significantly reducing the cost and time involved in full-scale...
Relating Angular And Linear Quantities - II
In the case of circular motion, the linear tangential speed of a particle at a radius from the axis of rotation is related to the angular velocity by the relation:
Causes of Similarity-Dissimilarity Effect
The similarity-dissimilarity effect, a fundamental concept in social psychology, explains how interpersonal similarities and differences influence attraction and social interactions. This effect is supported by three key psychological perspectives: balance theory, social comparison theory, and consensual validation.Balance Theory and Cognitive ConsistencyBalance theory, developed by Fritz Heider, posits that individuals seek cognitive consistency in their relationships. When two people share...
Gauss's Law: Planar Symmetry
A planar symmetry of charge density is obtained when charges are uniformly spread over a large flat surface. In planar symmetry, all points in a plane parallel to the plane of charge are identical with respect to the charges. Suppose the plane of the charge distribution is the xy-plane, and the electric field at a space point P with coordinates (x, y, z) is to be determined. Since the charge density is the same at all (x, y) - coordinates in the z = 0 plane, by symmetry, the electric field at P...
Relating Angular And Linear Quantities - I
If the rotational definitions are compared with the definitions of linear kinematic variables from motion along a straight line and motion in two and three dimensions, we can observe a mapping of the linear variables to the rotational ones.
When comparing the linear and rotational variables individually, the linear variable of position has physical units of meters, whereas the angular position variable has dimensionless units of radians, as it is the ratio of two lengths. The linear velocity...
When comparing the linear and rotational variables individually, the linear variable of position has physical units of meters, whereas the angular position variable has dimensionless units of radians, as it is the ratio of two lengths. The linear velocity...