XP

In most cases, fear towards a certain thing doesn't just manifest overnight. It is usually an acc.u.mulation of experiences that has lead to idea of fearing something which eventually manifests as fear.

Like why would a human fear something such as a spider (which is almost always harmless), unless it's due to a subconscious influence that we've grown up with. If you always hear people talking about how disturbing/creepy/scary/unnatural spiders are with their hairy legs, eight eyes, and eight legs, eventually you might even develop the habit of fearing them.

Even if we take into account that there is a substantial amount of potentially dangerous spiders, what about mice. Why do some people fear mice? This is probably because mice are commonly portrayed as plague and disease bearers. But the simple solution is; if you leave them alone, they won't bother you. If they're in your home, just call animal control.

(fun fact, lots of animals such as mice and bees can indeed smell fear)

(fun fact nr 2. mice fear females less than males and tend to be more bold around them and that would also explain why a larger proportion of females fear mice)

In the end the only reason a mice would end up attacking you is if you start to panick and start to scream and or attack it. It's probably just another case where fear has manifested due to subconscious influence as there is no real reason why a human should panic in the face of a mouse.

[Naturally I'm talking about the people who weren't directly affected by a traumatic experience]

Another example is; why would children hate vegetables unless it has something to do with how TV-shows portray vegetables as something disgusting that children shouldn't like? Or maybe it's because parents try so hard to convince their children to like vegetables because they're "healthy" which backfires due to children being rebellious.

The aforementioned topics are only examples.

Of course this is mainly just a short summary of my own hypothesis regarding this phenomen of unnatural fear or disgust that isn't exactly natural.