  We propose a quantum-mechanical model that represents a human system of
beliefs as quantised energy levels of a physical system. This model underscores
a novel perspective on opinion dynamics, recreating a broad range of
experimental and real-world data that exhibit an asymmetry of opinion
radicalisation. In particular, the model demonstrates the phenomena of
pronounced conservatism versus mild liberalism when individuals are exposed to
opposing views, mirroring recent findings on opinion polarisation via social
media exposure. Advancing this model, we establish a solid framework that
integrates elements from physics, psychology, behavioural science,
decision-making theory and philosophy, and also emphasise the inherent
advantages of the quantum approach over traditional classical models. We also
suggest a number of new directions for future research work on
quantum-mechanical models of human cognition and decision-making.
