SGA's Sheppard canonically does a fair bit of young-seeming things. There are scenes of him playing with toy cars, debating Bat villains, pushing coworkers off of balconies, etc. His quarters were furnished in minimalist college student: musician poster, guitar, novel. I can see where the 13-year-old in a 40-something body fanon comes from.
Dean, not so much. While he likes his pop culture riffs, he seems to unwind by drinking, watching medical soaps, and getting laid, not setting up an RC car obstacle course with Sam.
Both men have dangerous full-time+ jobs that require adult concentration and judgment. But on the off hours, their attitudes seem pretty different.
Dean does actually claim to be Batman. I don't think calling him a teenager in an adult body is at all far-fetched. He may be post-pubescent (cf: porn consumption, masturbation), but still pretty boyish in his downtime.
Or maybe I'm judging adult male pastimes like prank wars and stuffing your face with food as being boyish.
Although I might limit it to the first two.
Startled!Sam giggling makes
me
want to giggle. I'm totally pro it. Dean, not as much.
He may be post-pubescent (cf: porn consumption, masturbation), but still pretty boyish in his downtime.
He does like whoopee cushions and daring (and double-daring) Sam to drink gross stuff. I think Dean's got a ten-year-old boy in there who didn't ever really get to play. He would probably be psyched to set up some RC car races.
I think Dean's got a ten-year-old boy in there who didn't ever really get to play
That's exactly how I view it. He's got a continual low-level indulgence going on of something he never got to do at the time.
Hmmm. I see your point about the prank wars and face stuffing. Although we haven't seen much of that since season 2. I saw that sort of thing as remnants of his childhood relationship with Sam. With the Hell House prank war, didn't Sam refer to that as something they use to do?
Dean would probably be the better for a dozen afternoons of RC car races, but I'd mostly see him doing that in the context of caring for Ben.
When was the woopie cushion?
The whoopee cushion was in I Believe the Children Are Our Future, this past season -- the one with the kid, Jesse. He bought it and Cas ended up sitting on it. Heh.
From that episode:
SAM Okay, so whatever's doing this is—is reshaping reality. It has the powers of a god. Or—
SAM rolls his eyes.
SAM —of a trickster.
DEAN Yeah, with the sense of humor of a nine-year-old.
SAM Or you.
So, at the very least, S5 Sam rolls his eyes, and S5 Sam thinks Dean has a juvenile sense of humour.
The rest of his personality (okay, minus the self-esteem issues and the compulsion towards heroism) is what was made illegal in Blue Earth in 99 Problems, and are probably vices in which Sheppard would also indulge.
But I've always seen McKay as more childish anyway.
t /tangent
Hmmm. Looks like The Children Are Our Future pokes a hole in my theory. Oh well.
Okay, besides that Dean totally reminds me of my older brother (which is wrong on so many levels, considering whose girl I am) . . . I forget where I was going with that. Other than: Mature and capable adults are able to also be absolutely immature and irresponsible without reducing themselves to juvenilemisbehaviour. My older brother, due to certain circumstances, lost his later childhood. In his thirties, he is a giant kid who loves Christmas and birthdays and presents and doing stupid things, but is also an organized and efficient manager at his place of business. He works really freaking hard, but he also plays equally hard. And he's got the fucking eyelashes to beat the devil, bastard.