How do we optimize message matching interventions? Identifying matching thresholds, and simultaneously matching to multiple characteristics

Matching the content of persuasive messages to the characteristics (e.g., motives, personality) of people receiving them is a widely used technique to improve persuasion. However, little is known about how to optimize matching beyond simply using the technique. We propose that matching interventions can be strengthened by matching messages to multiple characteristics at a time, and introduce the concept of matching thresholds to improve the way interventionists assign messages. Matching thresholds are defined as the points along characteristics where people change from being most responsive to one message type to another. We provide statistical and methodological tools to estimate matching thresholds, and evaluate these tools in two simulation studies. We then report an online experiment (N = 568) where we find an advantage for simultaneously matching messages to two characteristics (promotion focus and interdependent self-construal) and provide estimates of the matching thresholds to guide the assignment of gain/loss frames and independence/interdependence appeals.