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A practical tool for designing effective policy interventions


There are many different theories which help us understand behaviour and change, drawn from many different disciplines. But there are fewer practical tools which allow practitioners to mobilise that theory, and apply it in developing and delivering behaviour change interventions on the ground.


ISM (standing for ‘Individual, Social, Material’) has been described as the most comprehensive of the available tools.

ISM is a multi-disciplinary tool for designing effective policy interventions, originally developed in the context of sustainability challenges. It was created by Andrew Darnton with 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).

The ISM Tool
ISM Tool

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 obesity, biodiversity, or social inclusion, where no one organisation or actor holds all the levers over a given behaviour.


The process of using ISM is as important in producing results as the content of the model itself. In essence, stakeholders gather around a shared behavioural challenge, and then work together to map the factors influencing that behaviour onto the ISM model. Through the process, stakeholders develop a shared understanding of the behaviour, and identify their respective roles in bringing about change. Because the factors on the model span multiple levels of influence, and because multiple stakeholders convene around the model to codesign solutions, the model offers an approach to behaviour change which begins to address the system (or ‘causal web’) within which the behaviour sits. As such ISM offers a way to bring about behaviour change which is more durable and far reaching, being grounded in system change. This way of working can have an effect on the most complex policy challenges.

The ISM process has been developed and trialled in the context of numerous behaviours in sustainability and health, and with partners including local authorities, DEFRA, DFT, Public Health England, the NUS, the Wellcome Trust, Scottish Natural Heritage, and diverse community groups. It is the Scottish Government’s behaviour change tool of choice, and has been mandated for all public bodies as they deliver their carbon budgets up to 2032.

ISM is freely available to all under a creative commons licence. For further reading, see the Scottish Government’s ‘ISM User Guide: Beyond the Individual’ and the accompanying guide to the underpinning theory. To see Andrew Darnton talking about ISM and its practical implications, see his presentation to the Institute of Engineering and Technology (IET)’s Behavioural Science in Transport Conference 2018.  For further support, contact Andrew at .

ISM in action


Academy of Change Podcast: AD talks ISM and behaviour models as guides for positive change 

AD presentation to the IET's Behavioural Science in Transport Conference 2018

Click here for the video


Each model or discipline suggests different avenues for intervention, and when faced with complex problems, we need to draw on as many as we can

Andrew Darnton wrote in his GSR Review 2008: “There is no one winning model”

We are faced with myriad models, so practitioners ask ‘Which one should I use?’

ISM is devised to bridge this divide: one single multi-disciplinary model

ISM was originated in Manchester SCI Review of International Behaviour Change Interventions (Southerton et al 2011)

ISM is designed as a practical tool: shortcuts theory (also, theoretical objections)

ISM as a Tool can be used throughout the policy / change process

ISM is especially suited to stubborn problems, systemic solutions

ISM Model
ISM Tool Individual Factors
ISM Tool Social Factors
Introducing ISM
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