Do a certain person die when a baby is born? (im curious..)

this is only from old hindu mythology but as far as i can c it is not true as if this would b the case the workd population wild nor have risin a single point as the balance would have applied by a hier force

Yes - it doesn't mean its related. They could be connected because of nature; or because of spirit.

This doesn't make sense. If that's the case the human population of the world would stay constant as opposed to keep increasing like today. As for the Indian belief of reincarnation I am not sure about that either. CMIIW, but the reincarnation involves not just human. So if a person is bad in the next life he might be demoted to an animal or something. If an animal is good he might be promoted to a human. Is that right? If that's the case then there should probably a research to prove whether the population of the entire living being on this earth stay constant or not which is pretty difficult to do.