Influencing behaviours: ISM technical guide

A technical guide to the individual, social and material (ISM) approach to influencing behaviours.


The ISM - Individual, Social and Material - tool and its associated user guide is intended to be a practical device for policy makers and other practitioners who want to influence people's behaviours and bring about social change. The purpose of this accompanying technical guide is to explain the theory underlying the model on which the tool is based, and to provide a fuller explanation of the different factors within the Individual, Social and Material contexts. This guide is therefore aimed at interested policy makers and practitioners who wish to achieve a better understanding of the ISM tool, as well as at those of a more analytical persuasion who are interested in the different theories and disciplines which underlie the model.

This technical guide is structured around the Individual, Social and Material contexts and the different factors within them. The guide opens with an introduction to the tool and its rationale.


The ISM tool has been designed to offer a practical alternative to the wide array of existing behavioural models and theories. The tool has been developed in the context of environmental sustainability and influencing people's behaviours so as to reduce CO 2 emissions and other impacts. However, it is also applicable to a range of other policy areas, including health and transport.

Policy problems are often complex, and solutions require a package of interventions, working across a number of levels. Examples can be found in relation to obesity (with the attention of practitioners focused on 'obesogenic environments' as much as the healthy choices made by individuals), and among pro-environmental behaviours (where recycling, for example, has become a normative behaviour as much through the provision of kerbside recycling collections as through the greener lifestyles of keen recyclers).

Just as there is no 'silver bullet' for changing behaviours in these areas, so it can be argued that 'there is no one winning model', or indeed winning discipline. Existing guidance recognises this - for example, the Government Social Research Unit's Behaviour Change Knowledge Review (Darnton, 2008) - but then leaves practitioners wondering which of the myriad behavioural models featured would best apply to the behaviour under consideration. The ISM tool attempts to shortcut that problem, by combining into one model the most pertinent factors and influences from multiple disciplines, in order to provide a practical tool for policy makers, practitioners and researchers.

ISM originates from the University of Manchester. It was first used in work for the Scottish Government in a report by the Sustainable Practices Research Group ( SPRG), which used ISM to examine the effectiveness of low carbon behaviour change interventions (Southerton et al, 2011). The ISM classification was further developed by Andrew Darnton in another Scottish Government project on low carbon workplaces (Cox et al, 2012). The user guide and technical guide take this further through providing a considered allocation of factors within the ISM contexts, together with full explanations, and the development of ISM as a practical tool.


The ISM Model


The three contexts of I, S and M can be understood as follows:

The individual context
includes the factors held by the individual that affect the choices and the behaviours he or she undertakes. These include an individual's values, attitudes and skills, as well as the calculations he/she makes before acting, including personal evaluations of costs and benefits.

The social context
includes the factors that exist beyond the individual in the social realm, yet shape his or her behaviours. These influences include understandings that are shared amongst groups, such as social norms and the meanings attached to particular activities, as well as people's networks and relationships, and the institutions that influence how groups of individuals behave.

The material context
includes the factors that are 'out there' in the environment and wider world, which both constrain and shape behaviour. These influences include existing 'hard' infrastructures, technologies and regulations, as well as other 'softer' influences such as time and the schedules of everyday life.

Theoretical Basis

The factors and influences which appear as labels in the model are principally drawn from three of the most prominent disciplines in studies of human behaviour: behavioural economics, social psychology and sociology, mostly theories of practice. The main aim of the model is to bring the three disciplines together in order to make it easier for policy makers and practitioners to draw on the insights from multiple disciplines, especially when faced with complex policy problems, where no one discipline is likely to have all the answers. Together, the three disciplines span the contexts of I, S and M, although they do not each map neatly onto any one context. It is also worth noting that the different factors are not arranged hierarchically in any order of importance.

Part of the practical strength of the model is that each of its underpinning disciplines offers a different view of human conduct and the role of the individual. Whilst it is obviously challenging to sum up entire disciplines within a few sentences, brief and simplified descriptions are provided as follows:

  • In behavioural economics, the individual takes the central role. The traditional economic representation is that of a 'rational man': an individual operating usually in isolation to maximise his/her own personal good. Behaviours are understood as decisions, which are ideally arrived at through cost-benefit calculations. In terms of theoretical constructs, behavioural economics incorporates ideas from other disciplines, mostly psychology, to provide decision-making principles which develop this traditional economic view. An example of this includes heuristics which describe the mental shortcuts people take in reaching decisions. However these can lead to systematic errors creeping into their judgement - this results in the less rational man of behavioural economics.
  • In social psychology, the individual is viewed more as a social animal, whose mental calculations are informed as much by emotion as cold calculus. Vitally, the individual also operates as part of a collective, behaving in ways which simply 'ape' the behaviour of important others. Nonetheless, behaviours are seen as choices, which ultimately flow from the motivations of the individual, and their identity as part of a group (or in opposition to a group). Social psychology provides myriad models of behaviour, which identify the factors (or 'barriers and drivers') which most strongly bring about the behaviour in question. These tend to be derived from 'attitudinal' survey data.
  • Theories of practice within sociology take social practices as the central focus of enquiry, and in so doing move individuals into the background. Social practices can be explained as patterns of action which bring together different ways of 'doing and saying'. No matter how many people are involved in undertaking a practice in a particular time and place, practices are always shared and social; people recognise a practice when they see it ( e.g. driving the kids to school, tumble drying laundry), and are therefore (more or less) able to reproduce it elsewhere - hence practices also tend towards the regular and routine. Recent work on theories of practice have better defined the common features that make practices coherent and which provide the basic elements that render them stable and recognisable: the materials, competences, and meanings which are already in circulation in everyday life. These come together to sustain particular practices, or split apart when practices fall out of daily use. Practice-based approaches to social change are therefore concerned with intervening at the level of elements, rather than pursuing individuals in order to change 'hearts and minds'.

These conceptual differences are a source of strength for a practical tool, as they open up different avenues for intervention. However, the attempt to bring them together in a single model or tool is also a source of tension on the theoretical level, including in the following ways:

  • By making the factors, influences and elements appear as equal labels on a single model, it could appear some equivalence was being implied between them. However, as we have seen above, the disciplinary understandings are fundamentally different. For instance, behaviour and practice are two alternative and incommensurate understandings of human conduct. Meanwhile 'drivers and barriers' assume a very different role to 'elements' in the process of acting. ISM should be understood as a pragmatic arrangement of diverse approaches to understanding behaviour in order to create a practical tool that makes the most of the different thinking that the disciplines have to offer. For theoretical purists, it is understood that the tensions within the model may be insurmountable. However, the purpose of the tool is not to find a way of unifying the theories, but rather to cut across them to create something derived from multiple disciplines which practitioners can use to achieve new insights and ultimately maximise behavioural impacts.
  • There is also debate over where specific labels should be placed on the model, and this also relates to the disciplinary angle from which one approaches the model. This is especially the case along the boundary between the Social and Material contexts, where exponents of practice theory might be tempted to place all but the 'hardest' labels ( e.g. 'Objects' and 'Technologies') in the Social context (as all practices are understood as shared and social). The authors have - after some debate - agreed to place, for example, 'Rules & Regulations' and 'Time & Schedules' in the Material context to highlight the extent to which they seem beyond the control of most individuals (albeit they are socially constructed). The ISM tool suggests that these influences form part of the 'soft infrastructure' which acts as a boundary to much individual behaviour and decision making - and over which governments are better placed than individuals to affect change.


The ISM model is presented as a tool to help achieve social change, which draws on multiple theories and disciplines. It is not theoretically pure, but a practical tool, developed not least as a corrective to some policy makers' and practitioners' tendencies to reach for single models from single disciplines when faced with complex problems. It is fair to say that we will not nudge our way to a solution to obesity, or build flood defences high enough to meet the ever-increasing challenges of climate change. However all these interventions, and the theories which underpin them, have a role to play as part of a multi-intervention approach to social change, grounded in multiple disciplines. The ISM model starts from an understanding of individual behaviour, but sets that within its social and material contexts, illustrating how action on multiple levels by multiple actors is required for inclusive and lasting change. It is hoped this guide makes the theory behind the ISM tool clearer, leading readers to understand more about behaviour and practice, and helping them to encourage practitioner colleagues to adopt ISM - and a wider definition of behavioural influences - when looking to design or improve policies and programmes.

" The ISM model starts from an understanding of individual behaviour, but sets that within its social and material contexts, illustrating how action on multiple levels by multiple actors is required for inclusive and lasting change."


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