In the psi encyclopaedia entry Patterns in Reincarnation Cases it says:
Sceptics of a reincarnation interpretation of the cases point to the association between beliefs about the reincarnation process and case features such as the presence or absence of sex change and argue that this is proof that people are imagining or constructing the cases in accordance with their culturally-mandated ideas. This proposition has been called the sociopsychological or psychosocial theory of past-life memory claims.
Stevenson noted that in his best cases the previous person lived in the same region as the current person. But there should be more cases where the previous personality is from a different nation, for there is no reason why deceased spirits should be constrained by space.
And he adds:
There are large cultural variations in the reports, and there is no reason why the characteristics of Stevenson’s cases should vary significantly from culture to culture. Such cultural variation suggests that the belief system of the culture determines the content of the reports. If a culture believes that sex change does not occur from one life to another, then it is not found in the reports.
So, should the reports be fabricated or mistaken, we would expect the characteristics of the cases to align with cultural expectations and desires. And that is precisely what we find. Should we conclude that the evidence therefore cannot be what it seems, that it does not point to reincarnation?
We cannot address this question until we have some inkling of what our expectations ought to be on this issue if, in fact, reincarnation does occur. Let's suppose we were not acquainted with any of the evidence suggesting reincarnation. What should be our prior expectations regarding what determines or influences the details of the reincarnational process? In other words, what is it that governs the sex we will be reborn as, where one is reborn, and what period of time elapses before one is reborn?
There seems to me to be three broad possibilities (or any combination thereof).
- Some impersonal natural "mechanism" largely, if not exclusively, characterises the reincarnational process. Such a "mechanism" determines what sex we are born, where we are born, and how long we stay in the otherworldly realm before we are reborn. Neither our thoughts, desires, underlying beliefs, nor any external agent, will have any significant influence in this process. Such a natural "mechanism" or process might be construed as being akin to the natural laws that describe our familiar material realm. For example, if we were to find ourselves in the unfortunate position of falling from a high height, our beliefs, desires, underlying beliefs and general psychological state will not be able to prevent us from stopping or slowing down our acceleration towards the Earth.
- Our desires, underlying beliefs, general psychological states, and hence our implicit expectations, do play at least some effective role if not exclusively determines the details of the reincarnational process.
- Some external agent(s) of some nature, wholly or partially, dictates the details of the reincarnational process.
If it can be shown that prior to looking at the research into reincarnation that it is more reasonable to subscribe to "1", or at least mainly "1", then this vindicates the skeptic's conclusion that the evidence for reincarnation can be dismissed. So we now need to look at their reasons for subscribing to "1".
Unfortunately, they don't give any reasons, or at least not so far as I am aware. Certainly, David Lester doesn't give any in his chapter in The Myth of an Afterlife where he argues against reincarnation. My suspicion is that skeptics expectations here are heavily influenced by their background suppositions about the world. Specifically, that consciousness, whether in the form of explicitly directed intentions or more vaguely in the form of psychological dispositions, plays no effective causal role in the world over and above material processes. The world, instead, is ultimately entirely governed by impersonal physical laws that are not directed towards any ends. So why should any supposed realm in-between lives be any different?
This idea that consciousness plays no effective causal role in the world over and above material processes implies that, broadly construed, some type of materialism is correct. Which then rules out the possibility of souls reincarnating. Thus skeptics, by imagining that it is entirely some impersonal process that determines the specifics of the reincarnational process, are to a certain extent, begging the question.
A world in which reincarnation happens entails that our essential nature is a soul. This, in turn, implies a world very different to the world in which the materialist imagines we live. In particular, it seems likely to me that in the afterlife realm our underlying beliefs, expectations, and desires will very much have an influence in what we experience and the environment we find ourselves in. And, should we reincarnate, influence when, where and what sex we will be when reborn.
This, of course, is just my belief, which could be incorrect. But we need reasons to suppose the alternative -- an impersonal "mechanism" -- would be mainly responsible. That neither a soul's beliefs and desires nor any external agent will play anything other than, at most, a minor role in this process.
Unless they are able to advance some cogent reasons, I therefore have to conclude that the cultural variations in the reports only constitute weak evidence against reincarnation.
Reincarnation and its Critics, Part 1: The Increasing Population
Reincarnation and its Critics, Part 2: Reincarnation isn't Falsifiable