Exploring the influence of different types of social norms and other factors on flood-adaptive behaviour

Floods pose a significant risk to societies, especially in Asia. Individual flood-adaptive behaviour can successfully reduce flood impacts. The literature suggests that perceived social norms influence adaptive behaviour, but how they do so currently needs to be better understood. Perceived social norms refer to an individual’s beliefs around (1) society’s approval of a behavior (injunctive norms), (2) what others do (descriptive norms), and (3) what important others expect the individual to do (subjective norms). This paper explores the role of social norms in adaptive behaviour alongside more commonly researched factors, such as threat and coping appraisals as described in Protection Motivation Theory (PMT), using structured face-to-face interviews with 351 randomly selected respondents from Vietnam. To better understand the role of social norms, we compare two theoretical models based on PMT, with and without the inclusion of social norms. Next, we apply a data-driven modelling approach in which covariates of the logistic regression model are systematically selected based on significance level and model performance. Results show that social norms significantly influence the implementation of flood-adaptative measures. However, the influential norms appear to be measure-specific: descriptive norms influence the preparation of emergency devices, while subjective norms influence livelihood adaptations. Different types of social norms and context-specific factors should thus be considered in well-established behavioural theories and risk policies aimed at enhancing flood-adaptive behaviour. • Social norms influence flood-adaptive behaviour in a measure-specific manner • Including three types of norms increases the explanatory power of the PMT • Coping appraisal and housing situation/location are among the influential factors • Risk policy could consider norms and factors that are tailored to specific measures