Interrogating side effects: The role of social information in treatment expectancies.

Negative expectancies play a key role in the symptoms people experience. Recent research has identified social information, such as media reports and written anecdotes, as capable of producing negative expectancies and subsequent symptoms. With the increasing availability of anecdotal health information online, and the increasing use of online sources in health or treatment-related decision making, this is a key concern. However, present literature on socially induced expectancy formation passively presents specific information to participants. In an online context, individuals actively choose to engage with certain types of information. The current studies were thus designed to investigate (a) what type of treatment information people typically engage with, when presented with positive and negative information, and (b) whether the type of information one selects relates to their subsequent treatment expectancies. Across three online studies, participants were presented with an information leaflet describing a medication and were then asked to select to read a number of anecdotes describing either positive or negative experiences of side effects associated with the treatment. Across the three studies, people selected relatively more negative than positive anecdotes. People who selected more negative anecdotes also had greater expectancies for side effects and worry about side effects. There was moderate evidence that selecting more negative anecdotes also decreased willingness to try the treatment. These results demonstrate that accounting for the type of information people tend to interrogate is crucial to understanding treatment expectancies and decisions, and suggest that valenced interrogation bias may represent an important cognitive mechanism contributing negative expectancies.