Video game controversies are societal and scientific arguments about whether the content of video games  change the behavior and attitudes of a player, and whether this is reflected in video game culture overall. Since the early 1980s, advocates of video games have emphasized their use as an expressive medium, arguing for their protection under the laws governing freedom of speech and also as an educational tool. Detractors argue that video games are harmful and therefore should be subject to legislative oversight and restrictions. The positive and negative characteristics and effects of video games are the subject of scientific study. Results of investigations into links between video games and addiction, aggression, violence, social development, and a variety of stereotyping and sexual morality issues are debated.