Threats to an animal come from different sources: from natural situations (e.g., heights and fire), from predation, and from members of the same species (conspecifics) that are in competition for resources. Social (or conspecific) anxiety may be viewed as one aspect of a defensive response system that evolved to deal with threat (Marks, 1987). Although anxiety conditions can be classified in various ways, in this chapter our emphasis highlights the differences between social anxiety and other forms of anxiety /fear.

First, consider the appraisal of threat. Non-social threat is conveyed largely through sensory information from sources such as smells, sudden sounds, or movements, and there may be little in the way of detailed cognitive processing. That is, there is a largely automatic component to these kinds of fear responses. Generally, however, social threats are not conveyed by sensory information, although scent marking of territory may be an exception to this rule, in that some animals show anxiety on entering another animal's territory (Marks, 1987). Social anxiety, on the other hand, at least in the higher mammals, depends on decoding complex social signals that require more detailed, less automatic, cognitive processing (Leventhal & Scherer, 1987; Ohman, 1986).

Second, the potential responses to social threats (e.g., shyness, embarrassment, shame) appear to be more complex and have undergone fundamental adaptations with the evolution of the reflective self-awareness that is allowed by consciousness.