Yep, that was one of the "tells" I told my youngest when he went to college.I call it danger hair.
It's like in the animal world when you have critters that are brightly colored and/or have striking patterns, something called aposematism. Think poison dart frogs, blue ringed octopus, even a good ole skunk.
I think the red part below is even more appropriate to the humans who display this trait than most other animals.
Poison.