I’d like to say something about the reincarnation beliefs and cases of animistic tribal peoples and how these differ from those found elsewhere.
Not many people realize how widespread animistic beliefs are—cross-cultural studies have found them in between one third and one half of tribal peoples living today (or at least when they were studied, usually sometime in the 20th century). The beliefs are found on every inhabited continent and in most culture areas of all continents except Europe.
There is every reason to think these beliefs are quite ancient and they have been the original reincarnation beliefs. They are different in some respects from other beliefs, and some of the patterns of tribal cases are also different, although interestingly, they are associated with the very same signs—announcing dreams, birthmarks, phobias, peculiar behaviors, memories of previous lives, etc. This makes sense to me, if the cases reflect something fundamental about human biology and psychology (reincarnation), but the beliefs regarding the process are the products of philosophical and religious thinking and theorizing.
One of the biggest ways animistic ideas differ from other ideas is in the absence of any notion of juridical karma, by which I mean the Indic idea that what we do or think determines the circumstances under which we are reborn and can impact us in various ways in this life or our next lives as a sort of natural law external to ourselves. Juridical karma is associated by many Westerners with reincarnation, but actually, there are other beliefs systems—the ancient Greek and Roman, for instance, and those of heterodox Shia sects like the Druze—that do not include this idea of karma either.
Animistic peoples also have a somewhat different idea of the spirit or soul. They do not think of the soul as something unitary and eternal, but rather changeable and potentially duplicatable or divisible. Typically, the spirit may also continue in the afterlife at the same time it—or an emanation from it—has been reincarnated in one or more children.
Their reincarnation cases closely resemble those found elsewhere, but some of the case patterns are different—an usually high percentage are in the lineage are clan and are classified as “family” or “same-family” cases. The cases may fall predominately on one side of the family or the other, however, depending on a society’s kinship structure—almost all cases from the patrilineal Igbo of Nigeria occur on the father’s side, but almost all those of the matrilineal Tlingit of Alaska occur on the mother’s side.
Reincarnation is very closely associated with lineal structures and with certain associated practices, such as cross-cousin marriage, and it is also tightly linked with naming practices and inheritance patterns. Why should that be? I argued in a journal paper that it is because these societies are set up to take advantage of reincarnation and the best way to assure that someone will have again what he had before is for him to reincarnate in the same clan and receive the same name, because names are considered clan property and are linked to property, rights and privileges. I found further support for this idea in my M.A. thesis, which tested various hypotheses about reincarnation in relation to social practices against a sample of 30 tribal societies.