Responding to international calls for critical thinking programs to address social polarisations and extremism through education, this article examines the cognitive and socio-psychological foundations of a critical thinking programme for secondary schools in England called “Living Well With Difference” (LWWD). The aim of LWWD is to develop critical thinking about issues of social polarisation, prejudice and any kind of extreme thinking. These issues often involve the interaction of emotion and thinking, which is understood using a dual systems framework, illustrated with examples of course methodology and content. The learning process aims to promote more cognitively flexible, complex and integrated thinking, measured by integrative complexity, and is supported by meta-awareness to enable emotion management. The aim is for participants to engage with difficult social issues through structured group activities, while becoming aware of social, emotional, textual, visual and rhetorical influences to increase Media Information Literacy, as a foundation for engaging with differing perspectives in order to reduce barriers between groups in society.