Social anxiety disorder (SAD) is characterized by marked anxiety about social or performance situations in which there is a fear of embarrassing oneself under scrutiny by others. It is a common disorder with early onset, significant comorbidity and functional impairment. SAD is a disorder with cognitive dysfunction in which a socially anxious individual's biased perspective-taking and expected failure to meet expectations in a situation result in the characteristic symptoms of the disorder. This book presents topical research in the study of social anxiety including assimilation and social anxiety in undocumented Mexican immigrant families; social physique anxiety; SAD in patients with schizophrenia and bipolar disorders; social anxiety and alcohol consumption; social anxiety and cardiovascular reactivity; and social anxiety in college students.