This study extended the findings of the 2002 study, “The Impact of Sign Language Interpreter and Therapist Moods on Deaf Recipient Mood” which initiated an examination of the impact of sign language interpreter involvement beyond the issue of facilitating therapist - client dialogue. Professional sign language interpreters are trained to be impartial conduits who neither add nor subtract from the primary dyadic relationship. However, the 2002 study found that despondent interpreter mood caused significant negative mood changes in the deaf participant even when the therapist mood was neutral / slightly cheerful. This current study examines the reverse: whether the mood and affective behavior of the deaf client and therapist can impact on the mood of the working sign language interpreter. Results indicated that the moods of both therapist and deaf client significantly impacted on the mood of the sign language interpreter. Furthermore, deaf client mood had a greater impact than the therapist mood on sign language interpreter mood. Findings suggest a potential for triadic influences in therapy settings. By perceiving, understanding, and utilizing those influences, the quality of the therapeutic alliance can be enhanced
