Generalized anxiety disorder (GAD) and social phobia (SP) are two of the major anxiety disorders identified by DSM-IV. They are highly comorbid and overlap in symptoms yet present with distinct features (e.g., worry in GAD and fear of embarrassment in SP). Given the overlap in symptoms and suggestions that conditioning-based accounts may explain all anxiety disorders, this chapter first evaluates whether hyperconditioning or hypersensitivity to threat is found in both or either disorder. On the basis of the current literature, this cannot currently be concluded in the case of GAD but may be the case for SP, as least for social-threat stimuli. The chapter then examines potential neurocognitive functions that might be aberrant in specific ways in the two disorders. Much remains to be discovered before any adequate cognitive neuroscience account of GAD can be considered. However, one form of neurocognitive function that appears markedly aberrant in SP relates to self-referential processing.