I’m an INTJ and for the longest time I couldn’t show emotion. (I felt them, I couldn’t show them.) Before I turned 17, my laughter consisted of polite chuckles and held back coughing-snorts. At one point, I think my ENFP (ENTP?) brother started wondering if I was depressed (or at least not experiencing happiness.) In the breadth of 2 months, he paid for two of my movie tickets for comedies (he was an adult who wasn’t living under the same roof as me).
On the way out of theater to his car, he asked me “How come I never see you laughing?” To which I didn’t have a good response. I remember thinking the words “I did enjoy the movie, I just didn’t laugh” but I didn’t say it.