Question

Dr. Morimoto is curious as to whether exposing people to violent video games causes them to be more aggressive. He assigns half his participants to play a video game for five minutes and the other half to play for seven minutes. He finds that there is no relationship between playing the game longer and being more aggressive. What might be to blame for this null effect?

Answer 1

He might have not been able to establish a correlation between playing videogames longer and being more aggressive because the difference between the experimental group (the ones who played videogames for seven minutes) and the control group (the ones who played for five minutes) is to small to be significant, only two minutes. Also, the amount of time to which the experimental group was exposed to videogames should have been longer in order to find a correlation between variables, if there is one.