title: Factor structure of the Tonic Immobility Scale in female sexual assault survivors: an exploratory and Confirmatory Factor Analysis.
abstract: Tonic immobility (TI) is an involuntary component of the fear response that is characterized by freezing or immobility in situations involving extreme fear coupled with physical restraint. The present investigation evaluated the factor structure of the Tonic Immobility Scale (TIS; Forsyth, J. P., Marx, B., Fusé, T. M. K., Heidt, J., & Gallup, G. G., Jr. (2000). The Tonic Immobility Scale. Albany, NY: Authors)--a newly developed measure to assess components of TI in female sexual assault survivors. Study 1 (N=88) consisted of an Exploratory Factor Analysis of sexual assault survivors' responses on the TIS, whereas Study 2 (N=191) involved a Confirmatory Factor Analysis (CFA) with a second independent sample of female sexual assault survivors. Findings from both studies suggest that the TIS is comprised of two independent factors: physical immobility and fear. Findings are discussed in terms of the theoretical and practical implications of the factor solution obtained, particularly with regard to evaluating TI in adult survivors of sexual assault.
authors.affiliation: University at Albany, SUNY, Department of Psychology, Social Sciences 369, 1400 Washington Avenue, Albany, NY 12222, United States. tiffanyfuse@aol.com
authors.forename: Tiffany
authors.initials: T
authors.lastname: Fusé
authors.forename: John P
authors.initials: JP
authors.lastname: Forsyth
authors.forename: Brian
authors.initials: B
authors.lastname: Marx
authors.forename: Gordon G
authors.initials: GG
authors.lastname: Gallup
authors.forename: Scott
authors.initials: S
authors.lastname: Weaver
mesh_terms: D000293:Adolescent; D000328:Adult; D005163:Factor Analysis, Statistical; D005239:Fear; D005260:Female; D006801:Humans; D046353:Immobility Response, Tonic; D008875:Middle Aged; D009129:Muscle Tonus / Q000502:physiology*; D016584:Panic Disorder / Q000453:epidemiology / Q000523:psychology; D011902:Rape / Q000523:psychology*; D015203:Reproducibility of Results; D013313:Stress Disorders, Post-Traumatic / Q000523:psychology*; D011795:Surveys and Questionnaires; D017741:Survivors / Q000523:psychology*; D014754:Violence / Q000523:psychology*