Theories of interpersonal sensemaking predict that cooperation emerges in interactions where speakers are matched on motivational frames and use a cooperative rather than competitive orientation. However, while there has been correlational research supporting the positive effects of motivational frame matching, this has not been investigated experimentally. This PhD thesis provides the first evidence of a causal link between motivational frame matching and cooperation and trust in an investigative interviewing context. Five experiments found that a cooperative orientation and motivational frame matching consistently led to more positive interaction outcomes (e.g., willingness to cooperate and trust the interviewer). However, within a competitive orientation interaction, the results were mixed. When participants were not actively involved in the interaction (Chapter 3), motivational frame matching during competitive interviews led to less positive interaction outcomes and this was largely driven by the relational and identity motivational frame matching. Conversely, when participants were actively responding to the interviewer at each interview round (Chapters 4-5), motivational frame matching led to more positive interaction outcomes, regardless of the orientation. Participants round-by-round interview responses showed that interacting with a matching interviewer led to more participant reciprocal matching, and this tendency was magnified in the competitive orientation interaction.
Chapter 6 moved out of the laboratory to examine authentic military investigative interviews. The communication behaviours within these interviews largely followed a cylindrical model structure, with instrumental, relational, and identity motivational frames being communicated across cooperative, competitive, and avoidant orientations, with different levels of intensity. Analyses of motivational frame matching found an interaction between confessions and the direction of matching: Interviews containing a confession saw more motivational frame matching by the suspect of the interviewer’s frames but not more matching by the interviewer of the suspect’s motivational frames; interviews where the
interviewer had received interview training—compared to interviews where they had not—contained more overall motivational frame matching.
In sum, the findings of this thesis suggest that motivational frame matching leads to more positive interaction outcomes and greater reciprocal matching, but that the orientation, as well the directionality of the motivational frame matching, matters for the size and direction of these positive outcomes.