Implicit relational aspects of the therapeutic relationship in psychoanalytic treatments: an examination of linguistic style entrainment over time.

Objective: In an attempt to operationalize an implicit aspect of the therapeutic relationship, this study assesses reciprocal linguistic style entrainment (rLSM) between the patient and therapist. rLSM is defined as the dynamic adjustment of function word usage to synchronize or to be in rhythm with another person as they change over time.

Method: In this exploratory study, levels of rLSM per talk turn were analyzed for 540 sessions of 27 long-term psychoanalytic treatments in relation to treatment outcomes.

Results: Within sessions, rLSM appeared to decrease by the end of sessions and followed a negative linear trajectory, β_linear= -0.0002, SE < .001, t = -13.04, p < .001. Between sessions, rLSM showed significant variability such that neither a linear, nor a quadratic, nor a cubic trend line fit the session-by-session change over treatment. On average, therapist talk turns had significantly lower rLSM than patient talk turns, while accounting for the nested nature of the data using multilevel models β_SpeakerT = -0.033, SE = 0.009, t = -3.65, p < .001. Levels of rLSM did not relate to treatment outcome.

Conclusion: Most of the rLSM variance was at the within-patient and within-session level. rLSM was no indicator of psychoanalytic treatment outcomes.