how much does learning a new language improve your brain?

No.14040032 ViewReplyOriginalReport
specially if it's something completelly different to your language, like farsi or japanese?

this man is 75 years old yet he seems very sharp
https://youtube.com/watch?v=TKg23ZFURX0

is this a secret way to be really big brained? learn 4 languages besides the one you know and your iq increases 20 points?

what would be the beast languages to learn if you already know a romance language (e.g. spanish) and english?