I recently came across a question of why would a dog have a fear of a smell. I answered with this story.
Years ago, I used to have this great white Samoyed dog named Rudi. We lived in the capital city area of Finland, where there is very few wildlife around for the dog to be afraid of.
One summer we went up North for hiking. We came across a steaming hot pile of bear poo (with berries and everything!). My dog sniffed around, all excited, and then suddenly his ears went all back, and he started pulling back to where we had come from, frantically.
I am pretty sure the dog had never, ever laid eyes on a bear, let alone fought one. So how did he know it should be afraid of it? I was not, I think, showing any tell-tales, as I was pretty assured the local bears were more terrified of our hiking party than the other way around.
The answer might be epigenetics . In effect, it is an inherited fear conditioning, linked, in this case, to the smell of the supreme predator. The fear of a smell was inherited from previous generations.
This blog post was originally an answer to a question on Quora. You can find the original post by me here!