In various formats, media have influenced children's development for hundreds of years. However, in recent decades media influence on children has steadily increased as new and more sophisticated types of media have been developed and made available to the public. Availability, as well as greater affordability for families, has provided easier access to media for children. Beneficial effects include early readiness for learning, educational enrichment, opportunities to view or participate in discussions of social issues, exposure to the arts through music and performance, and entertainment. Harmful effects may result from sensationalization of violent behavior, exposure to subtle or explicit sexual content, promotion of unrealistic body images, presentation of poor health habits as desirable practices, and exposure to persuasive advertising targeting children.