A latent trait approach to the development of persistent stuttering

The premise that stuttering disorders develop according to the orthogentic principle, preceding in a continuous, unilinear fashion from a state of rel ative lack of differentiation to a state of increasing differentiation and hierarchic integration, was examined. Responses to Woolf's Perceptions of S tuttering Inventory of 87 individuals who stutter were analyzed using a Ras ch 1980 latent trait model for dichotomously scored data. Analyses of respo nses indicated struggle, avoidance, and expectation through the development of stuttering that became increasingly articulated, integrated, stable, an d yet responsive to environmental changes. Four stages of development were noted: Stage I was characterized by the expectation of interruptions in the flow of speech, the addition of unnecessary sounds, and general body tensi on. Stage II was typified by distinctions between troublesome and not so tr oublesome words and sounds and between the speaker and various audiences an d contexts for speaking. In Stage III, speech control decreased despite mor e focused and complex efforts to control the environment and the speech app aratus. Stage IV was characterized by automatic scanning of all speech, inc reasingly uncontrolled body movements, and attempts to produce fluent speec h by way of comprehensive changes to sound, rhythm, and pitch. Follow-up of 29 respondents suggested the latent struggle was generally stable over tim e.