The Behavioural Drivers Model (BDM) is a practitioner’s map of why people do what they do, published by UNICEF in 2019 and written by Vincent Petit. Rather than proposing a new theory, it gathers more than twenty existing decision-making and behavioural theories into one diagram, sorting every driver into three categories: psychology (individual cognitive and emotional drivers), sociology (families, groups, communities and society) and environment (institutions, policies, services, infrastructure and information).
Redrawn for Deep Garden — after Petit (2019), UNICEF. Original at unicef.org ↗
The problem it was built for
Petit’s starting complaint is that behavioural theory rarely reaches the people designing programmes, so teams fall back on a default intervention, usually a communication campaign, whatever is actually driving the behaviour. The model is built to close that gap by linking every element in the diagram to something a programme can do about it. Its epigraph is George Box: “All models are wrong, but some are useful.”
Two levels
Level 1 names the main factors. On the psychology side these run along a decision pathway: cognitive biases filter what information gets considered, feeding interest, attitude and self-efficacy, which combine into intent, which limited rationality can still derail on its way to action and then settled behaviour. Personal characteristics sit above all of it. On the sociology side: social influence, community dynamic and meta-norms. On the environment side: communication environment, emerging alternatives, governing entities and structural barriers, with context cutting across.
Level 2 unpacks each factor into its dimensions, which is the level formative research is meant to work at once a community has identified which factors matter locally.
Meta-norms
The model’s most useful borrowing for deep disposition work. Taking the term from Robert Axelrod’s 1986 work on cooperation, where a meta-norm is a norm about norms that punishes transgressors, Petit widens it to the deeper, overarching norms that both create and maintain ordinary social norms: ideologies and unwritten rules entrenched in culture and identity, cutting across sectors, conditioning many behaviours at once, and expressed through derivative norms and through laws and institutions. Patriarchy is the report’s worked example, showing up downstream as child marriage, FGM and gender-based violence. Meta-norms are the layer that keeps stratification and power differentials in place.
Its own caveats
The report is unusually honest about being a simplification, and says so at length. It centres the individual rather than the community as the unit of change. Its left-to-right sequence implies more linearity than exists; the authors include a second diagram of what the model looks like without simplification, and call it a plate of spaghetti. No driver is weighted, because weighting is left to local formative research. As the report puts it, the BDM is offered as a tool rather than a theory, trading accuracy for usability, and users are warned not to treat it as a blueprint of how behaviours unfold.
Why it matters for deep disposition work
It is a rare diagram that holds the psychological, the social and the structural in one frame without collapsing them into each other, and it insists that intent converts to action only when social and structural conditions align. That is the same argument deep disposition work makes about why communications alone rarely shifts anything. Its meta-norms layer is close kin to what this project means by a deep disposition, arrived at from the direction of programme design rather than culture or narrative.
With thanks to Rose Shurman for suggesting we include this.
Also see Social Norm More, Schemas, Ecological Systems Theory, Shove's Triad and Cultural Hegemony