The impact of task decomposability in hypothesis testing within the psychotherapy session

In a psychotherapy session it is very difficult to decompose the flux of information in its parts, which favors holistic intuitive judgments (Hammond et al., 1987), and constrains the interpretation of subsequent information according to the initially activated scheme (Eyal et al., 2011). Thus, we hypothesize the clinical session leads to confirmatory hypothesis testing and favors primacy effects (Jacinto et al., 2016). In two studies, we manipulated the decomposability of a clinical judgment to elicit either end-ofsequence (EoS) or step-by-step (SbS) response modes (Hogarth & Einhorn, 1992). In study 1, participants listened to audio excerpts of fictional clients describing, in random order, depression symptoms and non-depression behaviors. The excerpts were presented uninterruptedly followed by a global judgment (EoS) or broken into six shorter segments (SbS). Hypothesis testing strategy was measured through participants’ likelihood ratings of three possible diagnoses. Study 2 followed a similar paradigm, additionally testing for the scheme activation by manipulating the order of depression symptoms (beginning vs. end of the excerpt). Results show that understanding the case in a non-decomposable way (EoS mode) leads to more confirmatory hypothesis testing strategy, but only when a scheme is activated (depression symptoms presented in the beginning). Implications to therapy session are discussed.