Where is this dour INTJ stereotype coming from? When they're around me, they do plenty of laughing. (We'll ignore the "at my jokes" or "at me" question for now.)
I think INTJs take day-to-day life more seriously, whereas I find the most inane stuff amusing. For example, there were all these birds chirping this morning when I woke up, and judging by the compressed squeaky chirps, they sounded like little fatties, like feathered balloons. Like little tennis balls.
This is what I imagined:
sadly, it actually made me giggle. If an INTJ heard me laughing at birds outside, they'd probably think I was some deranged bird lady.