Predictors of population uptake of health protective behaviours in RID epidemics have begun to be studied [8] [9] [10] [11] [12] [13] , yet related theory remains nascent and this is problematic: to effectively predict behaviour during future epidemics robust theory is critical. Effective models that enable comprehensive prediction of health protective behaviours remain limited mainly to two overlapping theoretical paradigms: the Theories of Reasoned Action/Planned Behaviour (TPB) [14] [15] [16] and Bandura's concept of self-efficacy [17] [18] [19] (the belief that one can successfully execute some behaviour), particularly regarding the core TPB concept of perceived behavioural control, which controversially is claimed by some to be largely synonymous with self-efficacy [19] [20] [21] and by others to be indistinguishable from intent [22] (the intention to execute a particular behaviour), the key predictive element of TPB [16] . When used to account for health-related behaviours TPBbased models typically account for ,35% of variance in outcomes [16] , while self-efficacy accounts for ,25% of variance in outcomes [23, 24] . However, neither TPB nor Self-efficacy allow for the social and affective influences that might be expected logically to be important in RID [25, 26] . We report on a theoretical model that incorporated elements of influenza causal knowledge, perceived self-efficacy and also social and affective influences ( Figure 1 ) because these latter variables have been less frequently studied in combination, but have theoretical and logical support for their potential importance in the context of RIDs. We tested this model against data collected in the early phase of the influenza A/H1N1 pandemic (Table S1 ) to examine how levels of trust in formal and informal sources of risk/prevention information associated with hand washing and social distancing.