A new study conducted in Singapore by Douglas A. Gentile, PhD; Dongdong Li, PhD; Angeline Khoo, PhD; Sara Prot, MA; and Craig A. Anderson, PhD; has found a fairly unmediated correlation between children playing video games and them having more aggressive tendencies 3-5 years down the line. Covering just over 3,000 children over a 3-year time period (73% male, 27% female), the study surveyed each child every year to try and gauge their game-playing habits and their susceptibility to aggression. The researches found that longitudinal latent growth curve modeling demonstrated a positive correlation between the consumption of violent games media and real-life aggressive tendencies, though they make particular note that this is primarily mediated by “aggressive cognitions”, rather than by the games themselves.
“Aggressive cognitions” appears to reference “normative beliefs about aggression, hostile attribution bias, aggressive fantasizing”, which effectively means that children’s thoughts on aggression and violence prior to playing games are the primary factor when determining the effect playing a violent game may have on them. Children who are more open to violence will see a stronger negative effect from playing video games, whereas kids who tend to be less open to or accepting of violence won’t see as strong an effect.
You can read the full study here if you like.