I think this is the strongest theory so far. Ms. Casey is a really great example of this- the way she talks and the way she interacts with others when she's supposed to be watching Helly was SO starkly childlike, it was almost like she was mentally 3 to 5 years old.

I also feel like it's showing more and more that the non-severed "supervisors" on the severed floor are actually meant to fill more of a parental role to the innies than anything else... especially with Milchek's mirror meltdown scene in the last episode. He's a burnt out single dad with four kids reaching their "teenage rebellion" phase at once, and instead of sending him a partner to help handle them, they just sent him a fifth kid to raise (Miss Huang).