How to not look less serious?

I look serious. I didn't know that I look serious until I started going to college and realised that people were avoiding me. Later my classmates revealed that they were intimidated by my appearance and thought that I only cared about studies and nothing else. Now I'm a PhD scholar and anyone can see that looking at my face. Most of the times people I meet already assume this about me even before I can introduce myself. According to people, I only care about important, intellectual stuff and there's no space for lighthearted nonchalance in my life.

I don't wear glasses (glasses often form this stereotype). However, due to cultural reasons and due to my rural upbringing I do have to dress more modestly (my neck, face, head, lower arms and palm remain visible) and I am very introverted as well.

My appearance makes me much less approachable and often people assume that I'm rude and snobbish. Are there ways that would make me look friendlier and nicer and not so serious?

Thanks in advance!

How to not look less serious?
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