In-group reassurance in a pain setting produces lower levels of physiological arousal: direct support for a self-categorization analysis of social influence

A large body of research demonstrates a strong social component to people's pain experiences and pain‐related behaviours. We investigate this by examining the impact of social‐influence processes on laboratory‐induced pain responses by manipulating the social‐categorical relationship between the person experiencing pain and another who offers reassurance. We show that physiological arousal associated with laboratory‐induced pain is significantly lower in normal, healthy participants following reassurance about the pain‐inducing activity when that reassurance comes from an in‐group member in contrast to reassurance from an out‐group member and a no reassurance control. These data are consistent with predictions derived from self‐categorization theory, providing convincing empirical support of its analysis of social influence using a non‐reactive measure. These data also represent a clear advance within the pain literature by identifying a possible common process to the social‐psychological component of pain responses. Copyright © 2006 John Wiley & Sons, Ltd.