The Tonic Immobility Scale in adolescent and young adult rape victims: Support for three-factor model.

Abstract

Objective: A substantial number of sexual assault victims report experiencing some form of peritraumatic tonic immobility (TI). A self-report questionnaire that is widely used to assess TI retrospectively is the Tonic Immobility Scale (TIS). This study explored the factor structure of the TIS in a clinical sample of adolescent and young adults. Method: The sample comprised 131 female rape victims, aged 13–25, who were referred for specialized trauma-focused treatment. An exploratory factor analysis (EFA) was performed. Results: The EFA showed support for a three-factor model, with factors TI, Fear, and Detachment. Item correlations ranged from.32 to.57 for TI, from.14 to.35 for Fear, and.29 for the two Detachment items. Conclusions: We found support for a three-factor solution distinguishing TI, fear, and detachment, suggesting the need to further develop the TIS with different subscales in varying age groups and clinical samples.