supporting evidence is correlational.
lacks a c&e r between aggression and violent computer games, no direct manipulation of IV and little control over other variables.
assumes the socialisation hypothesis that violent computer games cause people to become agg. However, the selection hypothesis might be a better explanation whereby people who are already agg select aggressive media like violent computer games because it suits their tastes.
If latter is true, aggression is not an effect of violent computer game play and instead agg is due to other factors (e.g., elevated testosterone)