As others have said, there is no need to try to link mass shootings with some evolutionary quirk. Not just because much of the unrigorous conjecture that comprises EP hinders its usefulness to science and our ability to understand ourselves, but also because the notion presented in the OP defies biological plausibility.
Most if not all of the folks who pull such moves end up being killed, either by their own hand or by others. Aside from that, their isolation often means they won’t have normal relationships with the opposite sex, and thus aren’t putting their seeds into the next generation. So what is the chances that a mass murdering predisposition would be a trait that would actually be selected for? It is something that should weed itself out if it has a biological basis.
That said, someone said something earlier in this thread that made me think, and perhaps this is what the OP is looking for, I don’t know. Here is the little story-hypothesis that came to me: One consequence of a large industrial human society is the increased likelihood that some people will become isolated, without a strong sense of community-centered purpose. The smaller the population, the more interdependent people are and the easier it is to feel like you have a place in society. But when the population gets too big, it increases the number of people who can’t find a constructive role to fill. These people gravitate to destructive roles. So they kill or create mayhem that leads to killing, almost in a subconscious attempt to bring down the population to a “happy” level again. Thus, mass shooters are created to be pressure valves so to speak. (Very, very ineffective ones, I might add…but hey I gave it a try.)
What’s wrong with “just getting the job done”? In my opinion, modern Western society overly-emphasis on so-called “being a team player”, “networking skills” , “communication skills” etc. even in many jobs that should not put these on priority. I think these additional requirements refelct that the fact that the job market today is a buyers’ market, i.e. employers’ market. During the earlier decades post-war it was overally a sellers’ market. Being a buyers’ market means there is an over-supply of potential workers, therefore the employers have a big pool of applicants to select from, so they enact these addtional requirements to further screen-out people.
It’s like modern day beauty pagenants. Physical attractive girls are plenty, nothing special, so they bring out these personality tests, talent tests, and answering social/politcal questions from judges etc. to screen-out and differentiate the contestants. In modern day job market, we can compare the physical beauty as the “hard” ability, with these “team-player” “networking skills”“interpersonal skillls” “communication skills” bollocks as soft ability. The latters are in fact, inconsequential, and in fact, can often be counter-productive in a work environment, after all, most of the ones who waste their time in the office chit-chatting with co-workers and doing other non-productive stuffs tend to be those “social”, “extraverted” people. Only reason employers use these soft-skills as requirements is because they want to further screen-out applicants because there are too many of them.
“Hard” skills no doubt are important. But being able to work well with others is not hardly inconsequential, sorry. It doesn’t matter how proficiently you flip those burgers. If you piss customers off, cause stupid conflicts with your co-workers, communicate in ways that promote confusion and distrust, you will suck at your job. Having strong interpersonal skills doesn’t mean you’ll necessarily be the most popular person in the office. It means you have the skill of creating relationships with others that maximize your own effectiveness in getting the job done, and an employer would have to be an idiot to ignore this quality when hiring people.
Aside from that, who wants to spend their 8-hour day with a bunch of antisocial bores? Should it be that surprising a friendly person who can make their co-workers laugh is a more attractive candidate than someone who would rather die than socialize, all other things being equal? I mean, this is life we’re talking about.
Mass shootings/mass attacks are far more common in some societies and less common in others. If it had some kind of evolutionary basis why would this be?