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The ISM model

The ISM model is a practical tool for designing effective policy interventions, developed in the context of sustainability challenges.  It was created by Andrew Darnton and colleagues at the University of Manchester, and launched by the Scottish Government in 2013.

ISM brings together into a single figure the main factors from the three disciplines most concerned with understanding behaviour: behavioural economics, social psychology, and sociology.  The factors are arranged into three contexts, symbolised by a head (the Individual) in a circle (the Social) in a square (the Material).  Evidence from reviews of international behaviour change interventions suggests that lasting change requires action in all three contexts (Southerton et al 2011).  
ISM was developed as a practical approach for intervening in complex systems, grounded in a deep understanding of behaviour.  ISM offers a shortcut to the task of drawing on multiple models and theories, resulting in a tool which policymakers, analysts and practitioners of all stripes can pick up and run with – including in self-facilitated sessions.  Used in this way, ISM supports approaches to policy development based on co-design and co-production – which in turn are vital for effective action in complex systems like climate change - where no one organisation or actor holds all the levers over a given behaviour.


The process has been developed and trialled in the context of numerous behaviours in sustainability and health, and with partners including local authorities, the Energy Saving Trust, Zero Waste Scotland, Scottish Natural Heritage, and diverse community groups.  

It is the Scottish Government’s behaviour change tool of choice; Andrew is currently helping the Government apply ISM to the task of delivering Scotland’s carbon budget for the period 2020-30 (‘RPP3’).  

Outside Scotland the model has been used by the UK Government (including DH, DFT, DECC), the NUS, and the Wellcome Trust.

For further reading, see the Scottish Government’s Influencing Behaviours - Moving Beyond the Individual - A User Guide to the ISM Tool

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