Reincarnation is not possible. You can prove that it's a myth early in in the philosophical stage. Who or what decides who gets to reincarnate and what counts?<br />
Secondly you can disprove it by the lack of knowledge we have. If spirits did exist then they should work like the iCloud storage system where they know everything and simply transfer it to the human host which would make life much better for all.<br />
The third point is where did all these new pla<x>yers come from? We have a positive population growth, so where did they come from? Ebay? The Flying spaghetti monster? The stork?
If you mean reincarnation as the material that composes your body, than yes. You decay and what you are made of is reused by the universe. As far as conciousness, I doubt it. That would require a memory storage system that is intangible. Many would reference that as the soul, but I know for a fact that if a human brain is damaged the right way, 'who you are' can become distorted. A quick slam the the frontal lobe, and you'll be incapable of emotion... we are very delicate.
Reincarnation is a pretty loose word. The energy that we are is constantly being transformed. That it comes back in human form makes sense. That we have anything to do with who we were before seems kinda doubtful. Who we are is mostly a brain function, and like a hard drive it stops when the brain stops.