In an effort to identify sources of stress reaction, a threatening film depicting a primitive genital operation was analyzed experimentally by dividing it into 3 sections of different contents. Impact of the sections was compared on physiological and psychological measures of stress reaction. The threat value of the film depended not only on the genital operation scenes, interpreted by previous investigators as producing castration anxiety, but also upon other types of contents, such as nudity. Moreover, in addition to differing in degree of disturbance produced, the film sections resulted in variation in the pattern of affects. Such patterns cannot be studied at the physiological level of analysis. Personality factors also determined reactions to the film threats. (PsycINFO Database Record (c) 2006 APA, all rights reserved)