The pairs watched about 20 minutes' worth of each movie. Group 1 saw some scenes involving guns, while group 2 saw scenes without guns.

Then the kids were sent into a play room to play.

In a cabinet in that room was a real 0.38 caliber handgun. Unloaded and disabled, of course, but real.

That most of the pairs, 83%, found the gun isn't very surprising.

But what happened when they found the gun was disconcerting.

The researchers counted the number of times the children pulled the trigger. The median was 2.8 trigger per kid pulls among those who watched the scene with guns. That's 2.8 too many in my opinion. There were almost no trigger pulls in the control group.

After adjustment for factors like age and sex, the researchers found that those exposed to the scene with guns pulled the trigger 17 times more often than those who watched the more benign scenes.

Children exposed to the movie with guns also held the gun longer – an average of 53 seconds vs. 11 seconds.

But there was quite a range in these measures. The authors report one pair of kids who gave the gun to study personnel right away, but then voiced regret about not keeping it to play with longer. In one pair, a child held the gun for 18 minutes and pulled the trigger 26 times, once against the temple of his partner's head.

The kids who had guns in their home were no more or less likely to play with the gun in the study. Nor were the kids who reported watching more aggressive media outside of the confines of the experiment.