The sensitisation model suggests paranoia is explained by over-sensitivity to social threat. However, this has been difficult to test experimentally. We report two pre-registered social interaction studies that tested i) whether paranoia predicted overall attribution and peak attribution of harmful intent, and; ii) whether anxiety, interpersonal sensitivity, and worry predicted attribution of harmful intent. In study one, we recruited a large general population sample (N=987) who serially interacted with other participants in multi-round Dictator games, matched to fair, partially fair, or unfair partners. Participants rated attributions of harmful intent and self-interest after each interaction. In study two (N=1011), a new sample of participants completed the same procedure and additionally completed measures of anxiety, worry and interpersonal sensitivity. As predicted, prior paranoid ideation was associated with higher and faster overall harmful intent attributions, whereas attributions of self-interest were unaffected, supporting the sensitisation model. Contrary to predictions, neither worry, interpersonal sensitivity, nor anxiety were associated with harmful intent attributions. In a third exploratory internal meta-analysis we combined data sets to examine the effect of paranoia on trial by trial attributional changes when playing fair and unfair dictators. Paranoia was associated with a greater reduction in harmful intent attributions when playing a fair but not unfair dictator, suggesting paranoia may also exaggerate the volatility of beliefs about the harmful intent of others.
|R Soc Open Sci
|Accepted/In press - 10 Feb 2020