Why do generally people have fear of heights

 Acrophobia describes an intense fear of heights that can cause significant anxiety and panic.  May be one of the most common phobias.

What causes it?

Acrophobia sometimes develops in response to a traumatic experience involving heights, such as:
Falling from a high place.watching someone else fall from a high place having a panic attack or other negative experience while in a high place. It will be registered in our subconscious mind. So whenever we see from heighted place, it triggers Acrophobia and cause fear.

Sometimes you may be more likely to have acrophobia if someone else in your family does. Or you learned to fear heights from watching the behavior of your caregivers as a child._