The final paragraph summarizes the argument put forth, but it requires further explanation:
The argument, built mostly on collected anecdotes and the single case of a thwarted shooter in Minnesota, is that Eric Harris wrote the playbook at Columbine, and it’s this playbook that’s motivating otherwise non-psychopathic teenagers to take up arms. Specifically, he suggests that it’s teenagers on the Asperger’s end of the autism spectrum who get caught up obsessing over school shootings in the manner that people with ASD tend to obsess over things.
It’s a compelling argument for the cases he picked, but is this a common enough scenario to do anything with?
Gladwell has always been the king of over-generalization. Here, he’s got one ASD guy who initially doesn’t fit a pattern, but turns out to have a disorder that manifested in his case as obsession and a lack of empathy, and maybe he wouldn’t have gone through with it anyway. How much of a pattern can we infer from him?
Certainly, there have been copycats inspired by Columbine. I don’t see from this article that school shootings are being perpetrated by a wider spectrum of kids, though, and frankly, I think seriously preparing to kill your family and your schoolmates is just about always going to qualify as “deeply disturbed.”
I’d say the frequency of the shootings and the publicity associated with them has helped widen the spectrum. Other societal factors are contributing also, but the copycat and one-upmanship nature of these crimes might be including a different group to act out now.