Mental health professionals have only recently begun to appreciate the staggering prevalence of child and adolescent psychopathology. One particular anxiety disorder that has received limited research attention and, yet, has significant consequences for youth is social phobia. Although research in the area of social phobia in youth is very limited, there has been a plethora of research examining this disorder in adults over the last several years. Theories concerned with the etiology and maintenance of this disorder have often focused on behavioral, cognitive and physiological factors. Although all three of these factors (behavior, cognitions, and physiological arousal) have been found to be related to social phobia in adults, there has been extremely limited research looking at whether these same three factors are related to social phobia in youth. Thus, the purpose of the present study is to examine the role that behaviors, cognitions, and physiological arousal play in social phobia in adolescents. Participants will be approximately 450 youth, 13 to 17 years of age and their parents. Participants will be recruited through flyers mailed to the homes of parents with youth enrolled in the public schools between the ages of 13 and 17. It is expected that approximately 225-300 of the youth will be classified into one of three groups (social phobic, socially anxious, and normal controls) using information gathered from diagnostic interviews and questionnaires. Youth in the three different groups will be compared with regard to their performance on several cognitive tasks (i.e, Stroop task and several memory tasks), physiological arousal (i.e., cortisol levels, heart rate, blood pressure, and body temperature), and behavioral skills during two behavioral role-plays (i.e., an contribute to the overall body of literature on social phobia, will extend the research investigating social phobia in adolescents, and will suggest important avenues for the development of effective treatment programs for youth with social phobia.