Nice review, and you're right to be skeptical about the large effect sizes in the behavioral research.

But I think I have a problem with this author's entire premise. Because gun violence in America, at least the kind that drives political discussion, is not regular street gun violence. No one cares about gun violence between gang bangers in Baltimore unless it can be used as a statistic to make a point.

The gun violence which drives the debate in America is mass shootings in schools. And these are all premeditated acts of deeply disturbed individuals, so the interruption theory isn't going to stop that. Unless he's trying to make a broader point about an uncaring, distracted society. (Where was someone to interrupt this child's descent into madness?)

Still, it's good to point out the contradictions in the data. More gun laws probably won't stop the gun violence, and it's probably correct to look at sociological factors.