This report sets out findings and lessons learned from an ambitious and innovative programme of work funded by the Education Endowment Foundation (EEF), the Royal Society of Arts (RSA), Arts Council England (ACE) and the Paul Hamlyn Foundation (PHF). At the core of the ?'Learning About Culture' programme are five school-based randomised controlled trials of arts-based education interventions delivered over four years, involving around 8,500 children in 400 state schools across England. These trials represent the biggest study of its kind ever undertaken in the UK and provide much-needed insight into both what works and how it works. The projects are The Power of Pictures -- Centre for Literacy in Primary Education (CLPE), The Craft of Writing -- Arvon, University of Exeter, the Open University, Speech Bubbles -- London Bubble, The Young Journalist Academy - Paradigm Arts and First Thing Music -- Tees Valley Music Service. They have been independently evaluated by a collaboration between the UCL Institute of Education and the Behavioural Insights Team, who worked with the developer teams, the EEF and the RSA, to design trials that would maximise what we can learn from the individual studies and reveal overarching findings from the trials relevant to evaluators, funders, arts-based education organisations and schools. [This report was co-produced by the Behavioural Insights Team of the University College London (UCL).]