Social distancing is unassociated with formal HPB messages, suggesting potential susceptibility to a ''herd-like'' response in this Chinese community, particularly if confidence in formal (government or doctors) information is low. Voerten and colleagues describe such a pattern of response in the early stages of SARS [25] . These models support the hypothesis that social distancing is more likely to occur when perceived health threat is high [25] . Logically, when others seem to be behaving in a way that is informed and probably consistent then their actions provide clear information. If mixed social messages occur signalling uncertainty then the utility of social information will fall. This is likely to be associated with increase perceived susceptibility, and possibly greater worry and distancing behaviour. This pattern of responses would be most likely early in a novel RID epidemic where disease characteristics and behaviour are often uncertain. High threat uncertainty then drives social avoidance of potentially high-risk others. High levels of worry are associated with greater social distancing. Around 50% of 997/14,297 (response rate 7%) British respondents agreed that social avoidance would minimize risk of A/H1N1 infection, and respondents reporting more anxiety were more likely to engage in preventive actions; severity and likelihood of infection were the most important determinants of preventive action [12] . Further research on social influences on HPB during epidemic and pandemic RIDs is warranted. Providing more knowledge about disease causes can improve hand hygiene but is unlikely to influence social avoidance, which appears less amenable to formal health messages. However, as formal messages achieve acceptance across the population, and uptake of HPBs increases, then under circumstances where a critical mass of the population are practicing precautions trust in informal information should increase, reducing susceptibility and worry and leading to declines in social avoidance. Because others are likely adopting HPBs this makes them less of a contagion risk. Conversely maintaining a high level of hand washing practices may require sustained public education activities. Finally, different segments of the population probably communicate different types of information with their peers.