The alliance-outcome correlation: Is there a halo effect?

Abstract

The working alliance between therapists and their clients is consistently associated with the outcome of the therapy such that symptom improvement is more likely when the alliance is rated more positively. However, this correlation could be inflated by biased alliance ratings. This study examined the experimental effect of outcome knowledge on observer ratings of the therapeutic alliance. Consistent with the halo effect, it was hypothesized that positive outcome knowledge would yield higher alliance ratings and negative outcome knowledge would yield lower alliance ratings relative to the control group. All participants (N = 168) watched the same video of a therapy session, followed by a randomized voiceover in which they either heard a detailed account of a positive outcome, negative outcome, or received no outcome information, before rating the alliance. Analyses revealed that participants in the negative condition rated the alliance significantly lower than participants in the positive and control groups. Findings were consistent with the halo effect suggesting that knowledge of a negative therapeutic outcome may bias observers' ratings of the alliance, which may have implications for psychotherapy researchers' coding procedures. Further questions about the validity of alliance ratings from other sources are discussed.

The impact of client distress on alliance ratings: An experimental test.

“…Further, the current study focused on state-like alliance, however, there could be important influences of symptom distress (i.e., outcome) on the alliance that are at the trait level for either client or therapist (see Zilcha-Mano, 2017). In addition, there could also be a “halo effect” in which knowledge of symptom improvement might lead to more favorable ratings on other processes like the therapeutic alliance (Lokhorst & Reich, in press).…”