My research interests lie in developing and applying theory to understand and change behaviour, with an especial focus on habit theory. My current research focuses on trying to locate the precise role(s) of 'habit' in social and health-related behaviours, and using habit-formation as a behaviour change technique and intervention goal.

I also research sedentary behaviour (sitting), especially in office workers, with a view to understanding why people sit for long periods and how to reduce sitting time in a manner suitable for real-world implementation, and conducive to long-term maintenance.

Dr Gardner undertook his undergraduate, postgraduate and doctoral studies at University of Sussex, and was awarded a DPhil (doctorate) in Social Psychology in 2008. His first post-doctoral position was in the Centre for Outcomes Research and Effectiveness at University College London (2007-09), where he worked on a series of projects that sought to use theory to develop understanding of health behaviour change techniques and interventions. In 2009, he became Lecturer in Health Psychology in the UCL Health Behaviour Research Centre, where he worked on a programme of theoretical and applied studies to develop habit theory and habit-based public health interventions. He joined KCL in 2014.