Matching the content of persuasive messages to the characteristics (e.g., motives, personality) of people receiving them is an effective 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 we introduce the concept of matching thresholds to improve the way interventions 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.Keywords: message matching; message tailoring; persuasion; matching thresholds; independent and interdependent self-construal; promotion and prevention focus OPTIMIZING MESSAGE MATCHING 3 How do we Optimize Message Matching Interventions? Identifying Matching
Thresholds, and Simultaneously Matching to Multiple CharacteristicsResearch on persuasion has a long-standing focus on identifying and optimizing strategies to improve persuasive communication, and one of the most well-documented strategies for increasing persuasion is message matching: altering the content of a message to match the characteristics, needs, concerns, and/or preferences of the individuals to whom they are delivered (Carpenter, 2012;Lavine & Snyder, 2000; Maio & Olsen, 2000;Noar, Benac, & Harris, 2007).For example, messages emphasizing the career outcomes of volunteerism are more persuasive for individuals highly motivated by career concerns, whereas messages emphasizing interpersonal outcomes are more persuasive for those highly motivated by social concerns (Clary, Snyder, Ridge, Miene, & Haugen, 1994;Clary et al., 1998;Joyal-Desmarais & Snyder, 2016). Message matching ensures people receive only the most personally relevant information, and has been used to influence many types of behaviors, including physical health (Gallagher & Updegraff, 2012;Noar et al., 2007), mental health (Lueck, 2018), consumer (Snyder & DeBono 1985), prosocial (Clary et al., 1994;1998), pro-environmental (Tangari & Smith, 2012, and political behaviors (Bertolotti & Catellani, 2014;Voelkel & Feinberg, 2018). However, beyond the general idea that matched messages are more persuasive, principles for how to design matched messages to maximize their effectiveness have yet to be specified (Updegraff & Rothman, 2013).We address this limitation by extending the message matching literature in several ways.First, we demonstrate that matching a message to multiple personality characteristics at once can provid...