Calculated IQ's of each board

I call bullshit.
You see, people of 4chin come to shitpost here, simply because they want to say things they can't say it IRL (or it is socially challenged to do so), so they come here to release or discharge such emotion, while the rest of the day, that individual could be a business owner, engineer, pharmaceutical, etc. So assuming the test criteria is scientifically proven, it would be still biased as it's like measuring someone IQ while he's pissed and ranting about something before he'll go to bed, additionally, it may even counted the summer months.
Now regarding the results in OP, I don't see any data sources or how it was conducted, so I would 90% assume that its basis is the average vocabulary or terminology used per post, and how coherent the paragraph is and maybe even the words count as well, that's why boards like /lit/, /out/ are amongst the top while image-based posts like /co/, /c/ or even Jow Forums labeled as low IQ. Basically, to get higher "IQ results" as per OP is to argue more with walltext shitposting.

i mostly browse Jow Forums, /lit/ and /sci/
i wonder what that says about my IQ

if that was the methodology it wouldn't make much sense for /wg/ to be so high

it also doesn't make sense for /f/ to be so close to the average since they pretty much have no discussion there - (still a pretty cool board though)

I'm thinking this is all arbitrary and made up

the two most notorious boards /b/ and Jow Forums have a good mix of very smart and very dumb people, just because they have so many users.

You could go to one thread with meaningful and insightful posts and go to another filled with derp

Not much, I'd say. But your post does tell a lot about your vanity.