system
A chat on subreddit /r/PoliticalCompassMemes
human
The only arguments I can think for putting it at 26 are 

1.) The brain doesn't stop developing until age 25 supposedly

2.) 26 is the cutoff for most children being on their parents insurance. Pushing this medical stuff out to that point ensures that no parent has to insure their child for this against their will. I'm not saying that would be possible to happen anyways, but I can see the argument pushing it out guarantees it won't happen.
gpt
I like the first part of this, the second part really just shows how yellow you are lol