Reciprocal language style matching in psychotherapy research

Successful coordination of language, that is language style matching (LSM; Gonzales, Hancock, & Pennebaker, 2010) indicated by interdependent use of function words, might be of particular relevance to the psychotherapy process. Empirically, two previous psychotherapy studies indicate that LSM may provide a deeper understanding of the quality of the therapeutic alliance. Theoretically, this process of implicit linguistic coordination may be conceptualised as interpersonal synergy (Riley, Richardson, Shockley, & Ramenzoni, 2011). To illustrate the potential of LSM in psychotherapy research, patterns of LSM per 5 min segments and reciprocal LSM per speaking turn were assessed in a seven-session treatment demonstration of a narcissistic client. First, LSM predicted observed frequency of ruptures but did not predict observer-rated working alliance in the corresponding 5 min segments. Second, LSM in these 5 min segments showed a quadratic trajectory of change within session and a stable pattern between sessions. Reciprocal LSM per speaking turn showed that within the majority of this treatment, the client followed the therapist's language style; however, this influence appeared to be bidirectional during the time of a physical altercation in session five. LSM may thus provide a novel way to study some of the more elusive aspects of the therapeutic interaction.