This research examined the effects of personality/social skills and individual differences in expressive style on impression formation. Particular attention was given to the role of nonverbal behaviors in the formation of initial impressions. Sixty-two subjects were measured on self-report personality and communication skill scales, on posed emotional sending ability, and on physical attractiveness. Subjects were then videotaped while giving a spontaneous "explanation." Trained coders measured five separate nonverbal cue factors displayed by the subjects in the videotapes. Groups of untrained judges viewed the tapes and rated their impressions of the subjects on scales of likability, speaking effectiveness, and expressivity-confidence. Male subjects who were nonverbally skilled and extraverted tended to display more outwardly focused and fluid expressive behaviors, and made more favorable impressions on judges, than did males who scored low on the measures of nonverbal skills and extraversion. Females who were nonverbally skilled displayed more facial expressiveness, which led to more favorable initial impressions. Sex differences may reflect basic differences in the acquisition and use of expressive nonverbal cues by males and females.