Because alcohol can profoundly alter motor control and behavior (by blocking inhibitions, for example, and releasing aggressive behavior), it is one of the most dangerous drugs. A large proportion of arrests in the United States are for driving while under the influence of alcohol, and a high proportion of crimes of violence (e.g., child abuse, homicide, and suicide) are committed by people who have been drinking. In the United States, members of minority groups (with the exception of Asian Americans) are affected disproportionately by alcohol-related problems. At different stages in the course of the disease, the alcoholic may experience problems with family and friends, absenteeism and reduced productivity, accidents, violent behavior, increased tolerance and consumption, or blackouts (periods of alcohol-induced memory loss). As the disease progresses, more and more serious physical and social problems may emerge.