Change health messaging to focus on potential impact to help stop the next pandemic

Uncertainty about how our choices will affect others is a common occurrence in our social lives, with previous research suggesting that such uncertainty leads to solely selfish decisions and actions. However, the new study found for the first time that uncertain situations do not always lead to selfish behaviour. Appealing to people to think about the impact of such potentially harmful actions can lead to decisions which err on the side of caution. The paper is published in Nature Human Behaviour.

When it comes to social decisions, the uncertainty we face can be split into two types, known as outcome uncertainty (i.e. uncertainty about the outcomes of decisions) and impact uncertainty (i.e. how an outcome will impact another person).

The researchers found that by focusing on messaging which appeals to impact uncertainty, and not outcome uncertainty, participants reported that they would be more willing to adopt behavior that would help contain the threat of infectious disease, highlighting the relevance of the findings for addressing global threats. This discovery could also enable public health officials and policy makers to nudge people towards less selfish decisions when faced with such issues.

To explore how people responded to impact and outcome uncertainty, the researchers carried out a series of experiments which varied the information participants received about the people potentially affected by their decisions. The results suggest that outcome uncertainty activates self-focused narratives that enable people to tell themselves that it is very unlikely their actions will harm another person, allowing them to reap the benefits of self-interested actions without feeling selfish. Such self-focused narratives can lead to selfish behaviour by downplaying the potential social costs of self-interested actions.

However, the findings suggest impact uncertainty activates other-focused narratives that include potential social costs, leading participants to adopt behaviors that preserve others' welfare. Notably, these narratives may cater for self-image concerns (e.g., "only a horrible person would risk infecting a vulnerable other").

Dr Andreas Kappes, a researcher at the Department of Psychology at City, University of London and lead author of the study, said:

"Uncertainty about how our choices will affect others is prevalent in all our lives, and we frequently are faced with such decisions. In our new study we found that when we are faced with uncertainty it does not always lead to selfish behavior, as instead, the type of uncertainty matters.

"Our findings suggest that when people consider the impact of their actions in such uncertain situations, such as harm they may cause by passing on a cold or flu, it can lead them to err on the side of caution. As a result, our findings offer new insights into communicating uncertainty to the public, especially in contexts in which behaviour that preserves others' welfare is paramount, such as infectious disease."