Researchers propose a new method of measuring the therapeutic alliance in psychotherapy: language style matching (LSM). LSM is defined as the degree of similarity in rates of function words in dyadic interactions and is thought to reflect the extent to which conversational partners are automatically coordinating language styles to achieve a common goal. LSM is calculated using the Linguistic Inquiry and Word Count (LIWC).
The researchers provide two exploratory examples of the application of LSM in long-term psychoanalytic treatments, demonstrating its clinical usefulness in measuring the implicit aspect of the therapeutic relationship. The results suggest that LSM might tap into a different aspect of the alliance, which is relevant for treatment outcome and different from the working alliance measured by observers. However, larger-scale studies are needed to further explore the relationship between these implicit aspects of the alliance and treatment outcome, and relevant clients and therapists' variables.