I would guess that the military's obsession with cleanliness and neatness also helps conserve executive function. Being in a messy, disorganized, visually unappealing environment probably puts a lot of strain on your visual cortex, which leaves less cognitive resources available for decision-making. Paul Graham wrote something similar:
A cluttered room saps one's spirits. One reason, obviously, is that there's less room for people in a room full of stuff. But there's more going on than that. I think humans constantly scan their environment to build a mental model of what's around them. And the harder a scene is to parse, the less energy you have left for conscious thoughts. A cluttered room is literally exhausting.
Keeping things neat and clean also serves as a reminder for a helpful kind of self image. If you're the kind of person who can't even properly keep your house clean, how could you possibly muster your willpower for any other challenges?
In response to the question
I posted that my military experience seems effectively designed to increase executive function. Some examples of this from myself and metastable are
Uniforms- not having to think about your wardrobe, ever, saves a lot of time, mental effort, and money. Steve Jobs and President Obama are known for also using uniforms specifically for this purpose.
PT- Daily, routinized exercise. Done in a way that very few people are deciding what comes next.
-Maximum use of daylight hours
Med Group and Force Support-Minimized high-risk projects outside of workplace (paternalistic health care, insurance, and in many cases, housing and continuing education.)
After a moment's thought it occurred to me that there are some double-edged swords in Military Rationality as well, some of which lead to classic jokes like 'Military Intelligence is an oxymoron.'
Regulations- A select few 'experts' create policies which everyone else is required to follow at all times. Unfortunately these experts are never (never ever) encouraged to consider knock-on effects. Ugh.
Anybody else have insights on the military they want to share here? I feel a couple of good posts on increasing executive function might come out of a discussion on the rationalities and irrationalities of the armed forces.