I think some people have this ability to glow too. And the glowing ones tend to notice each other. It's great when you get a bunch of "glowers" together. All kinds of light and sparks ensue.
Of course, as nature constantly reminds us, there is always the reverse too. What is the opposite of bioluminescence? Sorry, "no words found." But yesterday I walked into the coffeehouse and there at the table was a collection of the opposites. Dark holes. Black Cloud folks. I "know" them, know their names.
I walked past their table with just a nod. I could feel the darkness emanating from them, and it started creeping across the floor towards me. I spun on my heels, grabbed my coffee and decamped ipso facto pronto! Scary!