Our personalities are in large part how we define ourselves as individuals, influencing how we perceive, relate to and think about ourselves, our environment and those around us. Some of our personality traits may be determined by nature, some by nurture: as children we may demonstrate traits that parents or caregivers may choose to encourage or discourage. Over time, we perhaps adapt these traits and behaviors to fit in with those of our society, as they comprise the fluid aspects of our personalities. However, for some, during childhood or adolescence, these traits can develop into continuing patterns, expressed in ways that can cause clinically significant distress to the individual or those around them and impairing their ability to function in a variety of situations. If this is the case, the individual may have a personality disorder, which is pattern of outward behavior and internal experience that is decidedly different from how the individual's society expects people to behave. Around 30 million, or roughly 15% of adults in the United States have one or more personality disorders. Therefore, being familiar with the markers of a personality disorder is crucial for a clinician to recognize these traits in a patient, in order to make a diagnosis.