like more sure than just about any other character i’ve ever seen. i just got back from my second viewing and now i’m more convinced than ever. evidence:
adherence to routine: baby still eats at the diner where his mom worked, and he still orders from the kids menu. the waitress said that he’d been coming there for as long as she’s worked there; baby has basically lived his entire life around that diner, and he hasn’t updated his routine in years because the routine brings him comfort.
delayed echolalia: a significant portion baby’s spoken dialogue is actually just him repeating things he’s heard before in other contexts. we all do this from time-to-time, everybody likes a good quote, but baby does it… a lot. like, way more than normal. he seems FAR more comfortable speaking in quotes than he does speaking off-the-cuff.
immediate echolalia: and he doesn’t always store quotes for later. sometimes he repeats them back immediately. this kind of parroting is something autistic children have been known to do to help them process what is being said, not realizing that their repetition is being taken as a response. when doc asks baby “are you in?” and baby repeats “am I in?” almost automatically, you can tell this is an exchange they’ve gone through many times, likely going all the way back to when baby was a kid. perhaps that’s how it started.
memorization - this goes hand-in-hand with echolalia; you have to remember quotes in order to repeat them, after all. but it goes beyond mere snippets of dialogue; baby is able to memorize extremely complicated plans and rundowns and repeat them verbatim after hearing them exactly once. he does this twice; once when doc is telling the crew the plan, and once when he goes into the post-office and sam gives him the rundown of the security.
hyperfixation: baby lives and breathes music. owns dozens upon dozens of ipods that he has clearly gone through the trouble of buying off other people, each of which is loaded with different songs for different occasions and each individual library of which he has memorized. has keyboards and turntables and other mixing tools to create his own music, has a huge case of tapes of his own stuff, and a wall of vinyl records he’s collected. choreographs his getaway driving to music. hell, choreographs his entire lifeto music, to the point where baby has to stop what he is doing to restart, rewind, or find a song multiple times over the course of the film, even when his actual life is in jeopardy.
sensory issues: constantly listens to music to drown out his tinnitus. for many people, the ringing from tinnitus is something they can get used to and ‘tune out’ so to speak. baby’s inability to do this suggests that either his tinnitus is more severe, or he has some form of sensory disorder that prevents him from ignoring unwanted stimuli, forcing him to override it with something else.
savant syndrome: there’s really no way around this; baby is goddamn driving prodigy. if he were a middle-age man, his skill would put him among the best in the world; the fact that he’s this good now, and that he’s been this good since he was an actual child puts him so far into the stratosphere that we can’t even see him anymore. like, sorry, kevin spacey, but it’s not baby’s personal playlist that makes him the best driver on the fucking planet; there is something else going on in that kid’s brain, and whatever it is, it ain’t normal.
add all of this to the fact that baby’s intense focus and quiet, seemingly emotionless demeanor makes his criminal associates suspicious of him to the point where various idiots accuse him of having ‘mental problems,’ being ‘not on planet earth,’ with one particularly dumb asshole even throwing the R-word at him, and I’d say at the very least you have a strong case for baby being anything but neurotypical.