A synthesis of evidence for policy from behavioural science during COVID-19

Scientific evidence regularly guides policy decisions1, with behavioural science increasingly part of this process2. In April 2020, an influential paper3 proposed 19 policy recommendations ('claims') detailing how evidence from behavioural science could contribute to efforts to reduce impacts and end the COVID-19 pandemic. Here we assess 747 pandemic-related research articles that empirically investigated those claims. We report the scale of evidence and whether evidence supports them to indicate applicability for policymaking. Two independent teams, involving 72 reviewers, found evidence for 18 of 19 claims, with both teams finding evidence supporting 16 (89%) of those 18 claims. The strongest evidence supported claims that anticipated culture, polarization and misinformation would be associated with policy effectiveness. Claims suggesting trusted leaders and positive social norms increased adherence to behavioural interventions also had strong empirical support, as did appealing to social consensus or bipartisan agreement. Targeted language in messaging yielded mixed effects and there were no effects for highlighting individual benefits or protecting others. No available evidence existed to assess any distinct differences in effects between using the terms 'physical distancing' and 'social distancing'. Analysis of 463 papers containing data showed generally large samples; 418 involved human participants with a mean of 16,848 (median of 1,699). That statistical power underscored improved suitability of behavioural science research for informing policy decisions. Furthermore, by implementing a standardized approach to evidence selection and synthesis, we amplify broader implications for advancing scientific evidence in policy formulation and prioritization.

Self-affirmation increases acceptance of health-risk information among UK adult smokers with low socioeconomic status

This study reports an experiment designed to test whether self-affirmation can overcome defensive processing of risk information in a sample of UK adult smokers with low socioeconomic status. Participants (N = 57) were randomized to either a self-affirmation or control condition before reading a government-sponsored antismoking leaflet and completing measures of message acceptance, intention, and self-efficacy. Participants' subsequent behavior (taking leaflets) was recorded surreptitiously. Results showed that the manipulation significantly increased message acceptance, intention and behavior, and that the effects of the manipulation on behavior were mediated through message acceptance and intention. The practical and theoretical implications of the findings are discussed in relation to the possible use of self-affirmation manipulations to enhance the effectiveness of smoking cessation interventions.

Self-affirmation reduces smokers' defensiveness to graphic on-pack cigarette warning labels

OBJECTIVE

Little is known about how smokers respond to graphic images depicting the health consequences of smoking. The authors tested whether smokers respond defensively to such images and whether allowing them to self-affirm reduces their defensiveness.

DESIGN

Young smokers (N = 87) were randomly allocated to self-affirm or perform a control task prior to viewing 4 images intended for future use on cigarette packs in the European Union. Measures were taken immediately postexposure and after 1 week.

MAIN OUTCOME MEASURES

Participants rated each image for threat and personal relevance. Once all 4 images had been viewed, they completed measures of intentions, self-efficacy, and perceived behavioral control for reducing cigarette consumption, negative thoughts and feelings about smoking, personal vulnerability to 6 smoking-related diseases, desire to quit, and plans to quit. At the 1-week follow-up, measures of self-reported smoking and desire to reduce consumption were taken.

RESULTS

Relative to controls, self-affirmed participants rated the images as more threatening and personally relevant, and they reported more negative thoughts and feelings and higher levels of control, self-efficacy, and intentions. Risk level moderated the effect of self-affirmation on relevance and intentions: Self-affirmation increased ratings on both measures among those who smoked more. In addition, self-affirmation moderated the threat-intention relationship, which was weaker in the self-affirmed group. At follow-up, motivation to reduce consumption remained higher in self-affirmed participants, but there were no differences in reported consumption.

CONCLUSION

Self-affirmation can promote less defensive responding even to visual material about well-established health risks such as smoking.

Self-affirmation and the biased processing of threatening health-risk information

Self-affirming before reading about the link between alcohol and breast cancer promoted increased message acceptance among young women at higher risk. Differences were maintained on variables measured up to 1 month later. Relative to their nonaffirmed counterparts, higher risk, self-affirmed participants had higher ratings of risk, imagination, intention to reduce alcohol consumption, and negative affect, such as fear, while reading the leaflet. In contrast, there were no differences between the groups on measures of broader message acceptance (belief in the link, evidence strength). Thus, self-affirmation promoted acceptance of the personal relevance of the message, a critical step in the precaution adoption process. Overall, the findings support the view that self-affirmation in an unrelated domain can offset defensive processing of a threatening health message, promoting central route persuasion and producing consequential and durable increases in message acceptance.