Modeling Human Decision-making: An Overview of the Brussels Quantum Approach Diederik Aerts1, Massimiliano Sassoli de Bianchi3, Sandro Sozzo3 and Tomas Veloz4 1 Center Leo Apostel for Interdisciplinary Studies and Department of Mathematics Brussels Free University, Krijgskundestraat 33, 1160 Brussels (Belgium) E-Mail:
[email protected] 2 Center Leo Apostel for Interdisciplinary Studies Brussels Free University, Krijgskundestraat 33, 1160 Brussels (Belgium) and Laboratorio di Autoricerca di Base, via Cadepiano 18, 6917 Barbengo (Switzerland) E-Mail:
[email protected] 3 School of Business and Centre IQSCS, University of Leicester University Road, LE1 7RH Leicester (United Kingdom) E-Mail:
[email protected] 4 Universidad Andres Bello, Departamento Ciencias Biol´ogicas Facultad Ciencias de la Vida, 8370146 Santiago (Chile) and Instituto de Filosof´ıay Ciencias de la Complejidad Los Alerces 3024, Nu~noa,~ Santiago (Chile) E-Mail:
[email protected] Abstract We present the fundamentals of the quantum theoretical approach we have developed in the last decade to model cognitive phenomena that resisted modeling by means of classical logical and probabilistic struc- tures, like Boolean, Kolmogorovian and, more generally, set theoretical structures. We firstly sketch the operational-realistic foundations of conceptual entities, i.e. concepts, conceptual combinations, proposi- tions, decision-making entities, etc. Then, we briefly illustrate the application of the quantum formalism in Hilbert space to represent combinations of natural concepts, discussing its success in modeling a wide range of empirical data on concepts and their conjunction, disjunction and negation. Next, we naturally extend the quantum theoretical approach to model some long-standing `fallacies of human reasoning', arXiv:1807.11036v1 [q-bio.NC] 29 Jul 2018 namely, the `conjunction fallacy' and the `disjunction effect’.