Effects of selective outcome reporting on risk perception.

The current study aimed to investigate how selective reporting of study results indicating increased health effects will influence its receiver's risk perception. Using the example of the Interphone Study from 2010 on mobile phone usage and cancer, an online experiment was conducted separating respondents into two groups. One group of subjects was informed selectively about a relationship between heavy mobile phone use and an elevated risk of glioma (brain cancer) only. The other group of subjects was informed about the full results of the analyses of glioma risk by cumulative call time, which suggests that other than for the heavy users, there were no statistically significant elevated risks related to mobile phone use. The results showed that selective reporting of risk information increased risk perception when compared to receiving the full information. Additionally, the selectively informed subjects revealed a stronger tendency towards overgeneralization of the 'elevated brain cancer risk' to all mobile phone users, although this did not extend to an overgeneralization to other electromagnetic field sources or differences in the perception of a usage time dependency for possible health risks. These results indicate that reporting of full results is an important factor in effective risk communication.