This study examined the relationships among generalized expectancy for internal or external control, situational expectancy of control over aversive stimuli, trait anxiety level, and state anxiety reactivity. Seventy-two male subjects, selected from the upper and lower halves of the distributions of scores from the I-E and STAI A-Trait Scales, were randomly assigned to one of three conditions of expectancy of control over electric shock. Repeated measures of state anxiety were taken at three points in the experiment, and subjects were asked to rate the degree of control they expected to have in avoiding shocks. Results, based upon analyses of variance, were interpreted as strongly supportive of the use of the interactionist model in understanding the manner in which personality trait and situational variables interact in the determination of subject expectancies of control and anxiety reactivity.