I think they turn into cranks much earlier. Part of this is that I think despite engineering not actually functioning that way, engineers can often get away with falling into cult logic (there is one true path) in a way that other disciplines are more resistant to. Look at hackerrank and whiteboarding- wtf is that if not straight cult logic.

As an engineer I resent that. The causation is reversed. I got into engineering because of my tendency to, uh, think independently, not the other way around. It just took a while for me to think independently about physics, politics, medical...take your pick, and arrive at independent conclusions.

I think this tendency is mainly one for /successful/ engineers, ones that society has repeatedly rewarded for completing engineering projects to the satisfaction of others. Somebody works hard through a couple decades of looking at difficult but project-based problems and coming up with solutions. These projects start small and well-defined ("design the least expensive $thing that can accomplish $goal using this library of components") but are of increasing complexity and eventually start to look a lot like politics and sociology ("build a team that is capable of creating a successful product for the $industry industry").

They succeed at all of them, possibly even because they are actually very smart, and so come to the view that life is a series of projects that can be completed successfully, after which they will be rewarded with money and admiration. When engineering projects of sufficient ambition cease to become available (there are only so many Channel Tunnels or moon rockets to organize and build), they jump sideways into other disciplines with this template. Often that other discipline is politics, and their methods and mental models are just wrong because the engineering that these people know (not all engineering) is about completing projects within constraints, but politics has poorly defined constraints and is not a "project" (because there is no end).

This isn't really limited to engineers. All of us are in danger of thinking that our experience has prepared us for more than it really has. If anything, its more of a danger for lawyers and MBA types.

Kind of both, I think.