Aline SayerMichael ConstantinoSally PowersLaws, Holly2024-04-262024-04-2620142014-0210.7275/3e2n-1b30https://hdl.handle.net/20.500.14394/17724Mutual influence within relationships is theorized as central to human development and functioning across the lifespan. Multiple theories posit a process of progressive bidirectional influence that results in greater similarity between dyad members over time, termed attunement. Yet attunement processes, from dyadic synchrony in healthy child development to partner influence within romantic relationships, are difficult to measure and model. One difficulty is that capturing information from both members of a relationship pair, or dyad, requires statistical modeling that appropriately accounts for the interdependence between them. The present study addressed this issue by putting forward a framework for modeling attunement processes between relationship members over time, and applied this framework to two distinct studies. The studies both tested whether attunement occurred in two large-scale dyadic samples, the first in a sample of newly-married couples, the second in a sample of psychotherapy dyads. Attunement was modeled both as an outcome (in Study 1) and a predictor (in Study 2), providing interested researchers with an analytic framework for using measures of dyadic attunement as either an independent or a dependent variable. Findings from Study 1 showed significant attunement in the stress hormone cortisol over the early years of marriage in newlywed couples. This finding is suggestive of bidirectional spousal influence over a longer term than previously tested, as other studies have only inferred attunement processes by finding covariation in spousal cortisol over a matter of days. This study also disaggregated cortisol fluctuations into discrete parts, allowing for tests of spousal attunement not only in cortisol level, but also in physiological response to a stressor. Findings from Study 2 also found significant attunement processes within patient-therapist dyads. Specifically, patient-therapist alliance attunement over time was predictive of better outcome for patients receiving psychotherapy for chronic depression. A major contribution of these studies was that they modeled theorized relationship processes at the level of the dyad, rather than emphasizing individual outcomes. This dyadic-level modeling of bidirectional influence in turn related to outcomes relevant to psychological health, which may have been obscured or undetectable with other modeling techniques.allianceattunementcortisoldyadic analysishierarchical linear modelingrelationship processClinical PsychologyPsychologySocial PsychologydissertationN/A