Like, would a person who laughs at "stupid" things definitely be immature? I don't think so... I think it depends on the person. I think having a good sense of humor is one of the truest indicators of high intelligence.
It really depends on the person and what you would consider "stupid". If you consider "stupid" jokes that are still about saying potty-words, then yes, they are most likely immature.
Yes, absolutely! Though some people are more serious than others, the things that entertain or amuse them usually are an indicator of how high their level of thinking may be. If they like Family Guy, steer clear. . .