Social anxiety is nervousness in social situations. Some disorders associated with the social anxiety spectrum include anxiety disorders, mood disorders, autistic spectrum disorders, eating disorders, and substance use disorders. Individuals higher in social anxiety avert their gazes, show fewer facial expressions, and show difficulty with initiating and maintaining a conversation. Trait social anxiety, the stable tendency to experience this nervousness, can be distinguished from state anxiety, the momentary response to a particular social stimulus. Nearly 90% of individuals, more of whom are women, report feeling symptoms of social anxiety (i.e. shyness) at some point in their lives. Half of the individuals with any social fears meet the criteria for social anxiety disorder. Age, culture, and gender impact the severity of this disorder. The function of social anxiety is to increase arousal and attention to social interactions, inhibit unwanted social behavior, and motivate preparation for future social situations.