I read a book a few years back about this very thing. The author had spent an entire life time travelling around the world documenting absolute proof of reincarnation. He only put cases in his book that could be proven beyond a shadow of a doubt. It was an extremely interesting book to say the least. 'Speaking in tongues' simply crosses over from a previous life. So too do certain reoccurring dreams, certain abilities that some people are just 'born' with, certain fears that someone might have for no known reason, etc. I have NO doubt about reincarnation!
You don't have a soul. You are a Soul. You have a body. ~C.S. Lewis