Your reasons are your own; I cannot tell you why you make the choices you make.  Not for this or anything else for that matter.  Only you can answer those questions.

It's evolutionarily built into you.

If humans had no fear one of your ancestors would've walked his stupid ass up to a group of lions and gotten turned into dinner and you wouldn't be here to be typing away at a keyboard. Animals also display fear, it's a survival mechanism.

The problem is it's such a powerful emotion (and it has to be, otherwise it wouldn't work so great) that it can hard to regulate.

Fear as long it's not life threatening can be overcome, but you're hard wired to react with some fear to situations that are uncomfortable or may pose a threat to you.

Emotion isn't a choice, I don't buy that, it's hard wired into. You can alter your responses to that, but it will always exist to some degree, just like physical attraction is not a choice (you don't "choose" to be attracted, go ahead and try to force yourself to be attracted to someone you find unattractive, see how far "mind over matter" takes you then).

Well I can tell you that I don't choose to be afraid. I love roller coasters because I love moving fast, but every single time I want to jump out and walk down because of the height. If you you say about value of life vs. payoff is true, why would I prefer to walk down the roller coaster, vs. just let myself safely fall on the train? Why would I sit on the ledge of a tall apartment just to try and overcome my fear?

Nothing happened to me as a kid which would make me fear heights, it's something I've always been afraid of, for as long as I can remember. Also I find that I'm more fearful of the safer ways to be high (like roller coasters) then the dangerous ones (like bungie jumping or sky diving).

You keep asking me questions that you ought to be asking yourself.  You made your choices, now it is up to you to understand them.  That you continue asking me these questions when I've told you more than once to look within yourself suggests to me an unwillingness on your part to comprehend yourself.  That unwillingness will only impede your progress.  At some point you set the parameters in your mind to respond fearfully when presented with certain stimuli.  Try to understand why you set those parameters where they currently are.  Not one else set them.  You chose to be afraid when those conditions were met just as you choose to confront your fears ineffectively.  Your conviction in trying to choose to no longer fear heights is simply weaker than your certainty to fear them.  But I cannot tell you why that is so, for it is your mind in question.  You made these rules for yourself, not I.  You are the only one answerable to your own free will.

Your brain is designed to catastrophise things. With early man, the person who decided that the rustling leaves was just the wind, got eaten by a tiger *. If you have a traumatic experience with something, especially at a young age, your brain is going to associate that with catastrophe, and boom, a fear is born.

You can also learn fears from others, ie, I learned my fear of spiders from my mother (also, had some traumatic experiences when I was younger... but already had the fear by that point).

It's not a choice, but it's not random. Fears do pass with experience, though. A common example of this is fear of flying - clocking up enough air miles tends to get people over this (particularly once they have enough for a free upgrade!).

* You can thank Stefan Molyneux for this argument

Fear is a natural instinct and how your mind and body warn you of danger, only psychopaths have no fear. how you handle fear is a choice and overcoming fears can be a choice.

For certain things, fear is a choice. For others it is purely instinct or force.

As an example, I fear why this is in the NSFW Section.

Fear is a choice imo. You could become a mindless drone and have no fear. If you were born without any senses at all it would impossible to feel fear imo.

My point is I didn't make these choices. I have always been afraid of heights, and I know it's irrational, but that's just the way it is. I'm calm enough to understand the situation when it happens, but I'm still terrified.

I'm not unwilling to comprehend myself, I just know that I have always been afraid of heights, and there's absolutly no reason for me to have convinced myself that height's are something to be scared of. My mind knows that if I fall I could die (even if falling off is impossible like on a rollar coaster), and when that happens my body reacts by being tense, emotional, panicked. I don't choose to feel this way, it's something pre-programmed into my head.

I'm telling you, I didn't choose to be afraid of heights. I'm telling you that you are wrong. Maybe you may have been able to confront your fears and just convince yourself that there is nothing to be afraid of, but to that I say what you think you were afraid of, wasn;t really fear. Fear is something irrational, it's a que that sets off a trigger in your mind for your body to adapt in a specific way. It's no different from smelling fire and knowing something is wrong, or smelling a phermone and being attracted to something.

I think some fears can be treated, like araknophobia, and many phobia's/fears are listed a psychological disorders in the DSM IV. However it's also accepted that many fears (like being afraid of the dark) are hard wired into our DNA because those who involuntarily feared the dark, didn't venture into it, and evolved due to natural selection.

My point is, some fears like darkness or heights (like mine) are not optional. They are hard wired into the mind. I'm telling you, that I feel you are wrong, and you didn't catch that point.

I agree 100%

My fear is heights, always had it, with no cue for fearing it. It's true that I fell from a tall tree when I was 6 or so, but I was terrified of heights before falling from that tree. The only reason I was up that high in the first place was because someone convinced me "there is nothing to be afraid of."

With that example of hard wiring the fear of rusling leaves, I think people who weren't naturally afraid of cliffs, or high places, tended to fall to their deaths a little more frequently then people like myself. However clearly many people without this fear lived on, otherwise we'd all be afraid of heights like myself.

To be born with or without senses, doesn't sound like a choice to me. In fact it sounds like the opposite.