Since their inception in the 1970s, video games have often been criticized by some for violent content. Politicians, parents, and other activists have claimed that violence in video games can be tied to violent behavior, particularly in children, and have sought ways to regulate the sale of video games. Studies have shown no connection between video games and violent behavior. The American Psychological Association states that while there is a well-established link between violent video games and aggressive behaviors, empirical research finds there is little to no evidence connecting violent behavior (extreme physical aggressive behavior) to video games. Since the late 1990s, acts of violence have been highly publicized about beliefs that the suspect in the crime may have had a history of playing violent video games. The 1999 Columbine High School massacre created a moral panic around video games, spurring research to see if violent video games lead to aggressive behaviors in real life. Some research finds that violent video game use is correlated with, and may cause, increases in aggression and decreases in prosocial behavior. Other research argues that there are no such effects of violent video games. This link between violent video games and antisocial behavior was denied by the president of the Interactive Digital Software Association in 2005 in a PBS interview. In the interview, he stated that the problem is "vastly overblown and overstated" by people who "don't understand, frankly, this industry". Others have theorized that there are positive effects of playing video games, including prosocial behavior in some contexts, and argue that the video game industry has been used as a scapegoat for more generalized problems affecting some communities. A primary concern about a potential relationship between violence and video games is that a significant portion of gamers is young, and as such, particularly impressionable. A large-scale study conducted in 2022 suggested that at least a quarter of all gamers is between 10 and 20 years of age.