Hey guys, interesting topic.
Most people would probably come into this shocked that such a thing could exist, but I seem to have a propensity for ending up in very strange situations and knowing very strange people, so as it happens, I'm experienced with a similar phenomenon. Namely Therianthropy.
The name Therianthropy comes from the greek therion (beast) and anthropos (man). It is a suprisingly widespread phenomenon in which people believe that they in some way are part animal. Most often I've seen it explained that they have both a human soul and an animal soul. I encountered this because I'm personaly acquainted with several people who believe themselves to be lycanthropes, werewolves.
After talking with these people extensively about their beliefs, and why they believe them, I have no doubt whatsoever that in the particular case of the people I know, the phenomenon is demonic in nature. I don't mean to suggest that all those who have posted in here are in a similar situation, and from what I've seen so far there are marked differences. I just wanted to explain my background somewhat.
Now, I'm something of an odd mix of believer and skeptic... I will leave open the possability of things that most people would discount out of hand, and I believe things that many people would consider pretty far out there. However, I also question everything and I use reason and logic to test things.
I can understand some of the things you guys have talked about, how you've felt different, drawn out, a different kinship than the people around you etc. I understand those things because I feel them as well. As a christian, however, the bible is the basis, the starting point, or litmus test for all of my views. So if I'm going to believe in elves, dragons, etc, I have to see where it fits into the biblical account. I'm even willing to give strong consideration to extra biblical literature such as apocryphal texts and psudoepigraphica.
Given that, I don't see where a non-human race such as elves fits in. They would have to have been created, like humans, at the beginning, and I don't see that. However, I do believe that humanity has changed over time, not in an evolutionary sense, but rather more in a de-evolution. That is, mankind has become lesser as the ages have passed. In that view it is possible, and I am willing to believe, that some lines of descent could retain more of the ancient greatness than others. Also it is possible that something like that could skip generations and reappear in a prodigy type of person (like Aragorn for a fantasy refrence

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Another factor involved in that I believe is that I believe there is a spiritual awakening that people experience different levels of. This sounds terribly new age I suppose, and I am not. I believe first of all that people who have truly experienced christ and the life transforming power of God through Jesus are awakened in a way that those who do not have that experience aren't. This may seem very obvious but I think we often don't realise the full extent and impact of the change that this works in us. Furthermore, the christian life is a progression, running the race, and fighting the good fight if you will, along that path, as we get closer, we experience things that open our eyes, and broaden our horizons even further.. at least that has been my experience.
The only way I could account for non human descent in the gene pool would be the various incedents of nephilim and rephaim etc, and those are not good.