Does population growth invalidate reincarnation?

People who are acquainted with the theory of reincarnation are apt to look at the  increasing lifespan and the rising population on Earth and wonder if the population growth invalidates the theory of reincarnation.  We all know where babies come from but where are all the new souls which inhabit these bodies coming from?  In this article, we address this demand-supply problem.

There are three plausible explanations for why the theory of reincarnation still holds despite being subjected to the undue stress created by human reproductive prowess.

  1. The total number of souls may far exceed the number of incarnated souls. For example, there could be 100 billion souls currently in the life-death cycle out of which only 6 billion are currently living on Earth.  (Imagine the number of ghosts who are currently hovering around you as you read this article…!)
  2. There are animals which are evolving and taking birth in human bodies. Ancient Hindu scriptures aver that each individual soul which is Divine in nature undergoes a gradual evolution incarnating in plants, animals and then human bodies many times over, and that this process transpires over millions of years.  The period spent in afterlife can vary with intervals ranging from a few years to a few hundred years.
  3. There could be souls migrating to be born on earth from other planets in the Universe.   For more on this aspect,  see the article by theosophist David Pratt referenced later on.

David Bishai of the Johns Hopkins School of Public Health attempted to address this question in his 2000 paper “Can Population Growth Rule Out Reincarnation? A Model of Circular Migration” published in the Journal of Scientific Exploration.  Applying a Markov model to historical demographic data of the last 52000 years, he showed that population increase can be explained by a decrease in number of years  that are spent in the afterlife.  This hypothesis was first proposed by noted reincarnation researcher Dr. Ian Stevenson and has been incorporated into a sound mathematical model by Bishai.

Here is a quick layman summary of Bishai’s result.  Imagine there are 100 billion souls.  A few centuries ago, assume there were 500 million people on Earth with an average lifespan of 33 years, and the number of years an average soul spent between incarnations was (say) 5000 years.   Fast forward to the current scenario where there are 6 billion souls with an average lifespan of 70 years.  Then the number of years an average soul spent between incarnations will go down from 5000 years to 712 years but it doesn’t change the dynamics of reincarnation drastically.  Those who are mathematically inclined can read Bishai’s paper — Can Population Growth Rule Out Reincarnation? A Model of Circular Migration.

What could be the possible reason for a decrease in the time spent in afterlife? To understand that, one has to examine the after-death process.  The human constitution is made of  layers of five concentric sheaths, and upon death, each of these sheaths dissolve one after another over time (first the physical, then the vital sheath, then the mental sheath, and so on) until the soul itself retires to what Sri Aurobindo called the psychic world for a many years.  This is the normal process but it can be subverted if the soul has a strong attraction (e.g. unfulfilled desires) to return to the earthly material plane in which case the time spent in afterlife can be shortened and the soul is reborn immediately without rest after a few years.  It is quite possible that in this materialistic age, many people remain attached to their earthly possessions after death and are hence reborn quickly, thereby contributing to a population increase.  (So we have no rest at night, and no rest in afterlife  either – ugh!)

On the last factor mentioned above about souls migrating  to Earth from other planets, see  the two-part article by David Pratt, a theosophist, at  His explanation relies on the model of evolution conceived by H.P. Blavatsky.

See also:

  1. Spacetime in occult worlds
  2. Man the microcosm, Universe the macrocosm
  3. The occult spirits which influence our actions
  4. Ghosts explained
  5. Explaining out-of-body and near-death experiences
  6. Cosmology
  7. The occult forces behind artistic movements
  8. The latent Consciousness within Matter
  9. Are earthquakes due to Divine retribution?
  10. Sri Aurobindo and the Mother on Astrology


34 thoughts on “Does population growth invalidate reincarnation?

  1. Jose Maria

    I think that Sri Aurobindo has written in some letters that on average a soul rebirths in 3 years, where did you see hundreds of years?

    1. Sandeep Post author


      He did not say average time is three years. He said three years is the time it takes just to shed the earthly attachments, and beyond that it make take more before you reach the psychic zone. See Letters on Yoga, SABCL vol. 22, page 458

      The psychic does not give up the mental and other sheaths (apart from the physical) immediately at death. It is said that it takes three years on the whole to get clear away from the zone of communicability with the earth – though there may be cases of slower or quicker passage.

      I did not attribute “hundreds of years between incarnations” to Sri Aurobindo, because he says it is difficult to make any precise remarks. I might have read it elsewhere.

      Another thing to consider is that in the higher/subtler worlds, a year on Earth may feel more like an second, because time slows down as we go up the planes of consciousness. See Nature of Spacetime

    2. Sandeep Post author

      I found another reference on the question of years between incarnations

      As to rebirth, it must be confessed that no rule holds good for all cases. Some people are reborn almost immediately – it most often happens with parents that a part of them gets assimilated into their children if the latter are very much attached to them. Some people, however, take centuries and even thousands of years to be reincarnated. They wait for the necessary conditions to mature which will provide them with a suitable milieu. If one is yogically conscious he can actually prepare the body of his next birth. Before the body is born he shapes and moulds it, so that it is he who is the true maker of it while the parents of the new child are only the adventitious, purely physical agents.

      Source: (Collected Works of the Mother, vol 3, page 145)

    3. Sandeep Post author

      Another reference on time between reincarnations

      “The more evolved the psychic is, the nearer it is to its complete maturity, the greater the time between the births. There are beings who reincarnate only after a thousand years, two thousand years.

      The closer one is to the beginning of the formation, the closer are the reincarnations; and sometimes even, altogether at the lower level, when man is quite near the animal, it goes like this (gesture), that is, it is not unusual for people to reincarnate in the children of their children, like that, something like that, or just in the next generation. But this is always on a very primitive level of evolution, and the psychic being is not very conscious, it is in the state of formation. And as it becomes more developed, the reincarnations, as I said, are at a greater distance from one another”

      (Collected Works of the Mother, vol. 7, pp 86-87)

  2. nandhini

    Well I’ve been thinking about this problem for some time now and I think all those trees we cut ,all those ecosystems we destroy in the name of development not to mention the fast disappearance of many hundreds of species of plants and animals due changing climate and atmospheric chemistry-are reborn as humans. May be their individual evolution has been quickened due to our ruthless behavior(instead of spending a long evolution line being born as many species of plants and animals,these souls are awarded human form as its the only form we allow to live and learn).
    After all why should we care if polar bears and tropical frogs disappear from our planet right? Wrong!
    check this

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  5. Francois Pitre

    A way to look a this situation maybe be having a look at the distinction already clarified by Aurobindo between the soul and the mater.
    First and ever the Soul grow up his path throught latent Matter.
    Second: The result,”Life”, is basically a sort of gap between the Soul and Matter. The Mental appear after …

    From that point of view it is perfectly logical that a Soul may be working many pieces of matter in the same time.
    Some Soul may have to pass many reconstitution of Life before achieve their divine work.

    To look at it as a “problem” may also indicate a proeminence of Mental state. It is the only place where”Problems” are created.

    1. Sandeep Post author

      To look at it as a “problem” may also indicate a proeminence of Mental state. It is the only place where”Problems” are created.

      Well, I didn’t write it for myself 🙂 Out there in the world, there exist people with a passing acquaintance of reincarnation who raise such questions.

      Your general remark about the soul needing many reconstitutions (i think you meant reincarnations?) in order to become fully conscious is fine, but the numbers need to add up.

  6. Sandeep Post author

    This is the normal process but it can be subverted if the soul has a strong attraction (e.g. unfulfilled desires) to return to the earthly material plane in which case the time spent in afterlife can be shortened and the soul is reborn immediately without rest after a few years. It is quite possible that in this materialistic age, many people remain attached to their earthly possessions after death and are hence reborn quickly, thereby contributing to a population increase

    In this passage from The Life Divine, Sri Aurobindo elucidates why souls who are not mature could be reborn immediately.

    “In the early stages of a series of human reincarnations, during a period of rudimentary humanity, there is a certain possibility at first sight of an often repeated immediate transmigration,—the repeated assumption of a new human form in a fresh birth immediately the previous body has been dissolved by a cessation or expulsion of the organised life-energy and the consequent physical disintegrationwhich we call death. But what necessity of the evolutionary process would compel such a series of immediate rebirths? Evidently, it could only be imperative so long as the psychic individuality—not the secret soul-entity itself but the soul-formation in the natural being—is little evolved, insufficiently developed, so insufficiently formed that it could not abide except by dependence upon the uninterrupted continuance of this life’s mental, vital and physical individuality: unable as yet to persist in itself, discard its past mind-formation and life-formation and build after a useful interval new formations, it would be obliged to transfer at once its rudimentary crude personality for preservation to a new body….Yet we may suppose that there is a downward attachment so strong as to compel the being to hasten at once to a resumption of the physical life because his natural formation is not really fit for anything else or at home on any higher plane. Or, again, the lifeexperience might be so brief and incomplete as to compel the soul to an immediate rebirth for its continuance. Other needs, influences or causes there may be in the complexity of Natureprocess, such as a strong will of earthly desire pressing for fulfilment, which would enforce an immediate transmigration of the same persistent form of personality into a new body. ”
    (Sri Aurobindo. Life Divine, Rebirth and Other Worlds, CWSA, p 827)

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  10. Sandeep Post author

    Interesting TED talk on the subject of population growth.
    Hans Rosling : Religion and Babies

  11. G

    Could it also be that our high population is due to more souls are trying to reincarnate at the same time to save the Earth right now, but because of the dire situations in some parts of the world or the day and age which we live that they are being born into unfortunate circumstances and/or “forgetting” why they have come and thusly disrupting their own path by accumulating more “negative” karma?

    1. Sandeep Post author

      I seriously doubt that more souls are incarnating to save the Earth. Population is exploding for two primary reasons:

      1) People are living longer because health awareness has increased over the past few centuries. Before that, plagues, wars, etc. would reduce numbers rapidly.

      2) In the pre-industrial era, people used to have large families with 7-8 children. We are still seeing the after-effects of that historic trend. The birthrate typically reduces when women in a country begin to enter the workforce. This is called the demographic transition in official jargon

  12. Sandeep Post author

    A story in a talk given by the Mother:

    Here is a little story. One of my friends had made a trip to India and was requested to give an account of his travels. An old, very credulous lady was there and she asked him, “In India, do they count the souls?” He answered, “Yes.” “How many are there?” asked the old lady. He answered, “One only.”

    (Collected Works of the Mother, vol. 4, p 48)

  13. Kris

    Population growth is weakening my beliefs that there is a spiritual realm. Why would such a vast number of souls decide to inhabit the Earth at once? Are souls not able to see the destruction that we are causing? How stupid. The extreme boom in growth began during the Industrial Revolution, when survival became easier. This shows a purely physical reason why population growth is occurring. We are nothing more than ticks leaching the blood from this poor planet.

    1. Sandeep Post author

      Kris: Are souls not able to see the destruction that we are causing?

      No they can’t because not all of them are wise. Fertility rate falls with intellectual education of society.

      Kris: Population growth is weakening my beliefs that there is a spiritual realm

      The human mind is intimately tied to the emotional being, so there will be days when all theories will seem false and nothing in the world will make sense. These phases of disillusionment disappear only when the Self(Atman) is found and the mind becomes quiescent. Until then, these theories and discussions are just a temporary support. Acceptance of reincarnation is not a prerequisite for the spiritual journey.

      Remember the words of the Buddha:
      Do not believe in anything simply because you have heard it.
      Do not believe in anything simply because it is spoken and rumored by many.
      Do not believe in anything simply because it is found written in your religious books.
      Do not believe in anything merely on the authority of your teachers and elders.
      Do not believe in traditions because they have been handed down for many generations.
      But after observation and analysis, when you find that anything agrees with reason and is conducive to the good and benefit of one and all, then accept it and live up to it.

      1. Kris

        “In other words, people who did not develop spiritually in life tend to be reborn quickly with minimal rest between incarnations[5].”

        Perhaps the dwindling spirituality in humans is resulting in fast paced reincarnations. But if that is the case, that would mean that our spirits are selfish and single-minded. They feel that they need to come back to Earth to fulfill their own unfinished business without giving thought to the damage that our species is doing with this rampant reproduction. I went to the Natural History museum in D.C the other day and there is a section on human history. There is a digital counter on the wall of the human population. The number is constantly rising. It rose about 2,000 in the half hour I was there. There are sections throughout the museum on how this planet is changing because of our presence. From the mass extinctions of species to the changing of the climate, we are ruining the planet. How is that okay with God? Why would this be allowed? And why are such a mass amount of spirits concentrated in such a minute area of this vast universe? Why are they not more evenly distributed so as not to distroy the habitats of other living beings? Why are animals and nature getting such a kick in the butt? Does God care less about them? It all feels very off balance. I think of horrible people such as murderers that got the dealth penalty. What if they feel that their business of murdering is unfinished? Do they get to come back in another body and coninue to spread their voilence? If I were a god, I would halt the ability of humans to reproduce until the balance between us and this planet is restored.

      2. Sandeep Post author

        This reminds me a joke I might have read in “Reader’s Digest” : A person is giving a talk on how there is a woman giving birth every few seconds on this planet. Someone in the audience quickly responds, “She must be stopped!”.

        Sorry, couldn’t resist the digression 🙂

        Seen from our limited consciousness, the present imbalance does seem imperfect but we forget that the Earth has been through several cycles of destruction and rejuvenation, which have been recorded in the tree rings and ice cores. Our souls are on Earth to learn, and perhaps the present imbalance is providing opportunities for some of us (scientists, politicians, scholars) to reduce strife, and to develop new ways to survive with less food and water. Let us see where it leads. Perhaps a mass destruction followed by a pause in human civilization on Earth is also needed to help the planet heal itself.

        While the angst regarding the planet’s future is helpful to awaken the soul, one must transcend that concern as well and reach a state of equanimity (what the Gita calls Samata). It is only when we are happy within that we can find the answers to these pressing problems.

  14. Kris

    Haha, I like that joke 😉
    The weather cycles of the Earth were also presented at the museum. There was a graph that illustrated the climate cycles over the past millions of years. The line went up and down fairly regularly, but once it hit the 1900’s, the temperature line shot up drastically. This is not a natural cycle for the planet. It is the result of our careless, destructive behaviors. Our souls seem to be increasingly slow to learn. We are gravitating towards the fast paced world of technology and away from the essence of the Earth. We do not have to see where our food comes from, we do not have to deal with our trash piles, we do not immediately feel the effects of our carbon footprint; we simply live in our own little destructive bubbles. Look at how little climate change is being discussed and respected today. For many, it is still merely a laughable myth. We seem to be stepping back, not moving forward. There are some who are fighting to preserve what we have left, but most do not care enough to do anything about it. I agree that a mass destruction would give the planet a much needed breather. I wish that wasn’t the case, though. I wish our souls were in line with the planet so that we could be aware when our actions are causing destruction. I honestly feel no pity when I see the horrible damage done to cities by natural disasters. Our species deserves it. I am trying to reach equanimity, but it is so difficult right now. I am constantly surrounded by reminders of the state of our planet. I do not know how to reach happiness with this. I hope some enlightenment comes my way! Thank you for your responses. I am enjoying reading through your blog posts.

  15. Brian from Arizona

    Greetings Sandeep –
    My personal inclination is not to be overly concerned about deficiencies with respect to an intellectual model in which all the “technical details” of time, numbers and reincarnations can be made to fit. (I sense the same goes for you.)
    But I am nevertheless bemused by the discussion, since so much of it seems to presuppose an invariant concept of time. My own humble view (always subject to change, of course) is that time is entangled with space, form/substance and movement. And that being said, there is no reason to believe that those concepts mean the same thing, or “work” in the same manner (as a practical matter of experience) across the many vast worlds of existence.
    Perhaps this is just one of those things that exceeds the grasp of mental comprehension, and must thus be relegated to the realm of mystery? Some might find this to be an unsatisfactory state of affairs, but the notion of “mystery” is something with which I’m personally quite at peace.
    Kind regards,
    Brian from Arizona, USA

    1. Sandeep Post author

      Agree. This article was meant for novices whose minds are bewildered as to how reincarnation can be reconciled with population growth.

      The proof of reincarnation is ultimately to be gained from one’s spiritual experience.

  16. angy

    Hello Sandeep. I read your article and tried to compare it with Ian Stevenson studies. In summary, he noticed, that after death soul waits about 15 months to reborn.That is why I feel little uncomfortable about that, for me this conflicts with population growth.
    Here is the deal: I believe in reincarnation, and I am pretty sure, my previous body committed suicide. When I was about 3 years old, I came to my mother with a rope around my neck. I told her I want to die. Since it was in 90’s I can’t imagine, where it came from. I don’t actually remember I did that, but since I have a phobia – nothing possible around my neck. Week ago I had panic attack. I was so scared about my possible death, I felt myself very bad and I went to psychiatrist. Next two days I saw everything like – you die, I die, we all die. I became so crazy so I did some research and Stevenson’s studies were first I read. I did some calculations. Counting 15 months back from my birth I got the same day I had this attack. I started to believe, that may be, my soul remember that suicide and because of that I felt this shock. Because it was first time I felt something like that, I believe, last me died is same age I am currently. Since now I am under sedatives and feel myself better, but I still can’t reduce myself. Funny fact, I did not actually born in the day I should. They took me out 2 weeks later because I did not want to born. I always made jokes about that – I was lazy before I born. But maybe, there is other reason.
    I write all of this, because I still feel myself very badly. And I want to find kind of believe I can stick on.
    So, here is my question: If body commits suicide, how this corresponds to the soul? If our brain works like receiver, and my soul did not want to die so quickly, then why it is all happened? According to Ian studies, 15 months took place if someone were murdered or something. I understand murder, but cannot accept suicide in that way then.
    But of course, those are just my toughs.
    I am sorry and thank you for you answer. And thank you for your post.

    1. Sandeep Post author

      I would urge you to stop thinking too much about the circumstances of your last life. It is not possible to be certain about what happened. We absorb influences from all around us (television, horror movies, novels) and start fantasizing about things which might have happenned, inevitably reaching the most alarming conclusions. As a child, you might have picked up the idea of a noose from somewhere and now it has turned into a phobia.

      If you keep getting anxious like this, your mind will start justifying every fantasy and upgrade it into a fact or truth.

      Suicide is not helpful because the soul keeps returning to new births until it has overcome the emotional weakness and despondency which caused the suicide. There is the case of Satprem, a French disciple of Sri Aurobindo, who had committed suicide in previous incarnations. He kept being haunted by the thoughts of suicide until the Mother healed him and restored his health and well-being. He lived well and practiced Yoga and died recently at a ripe old age.

      So eat well, take long walks in Nature, hang out by the ocean, and stop researching too much on reincarnation (including articles on this blog!!) .

      We are reborn to conquer our weaknesses, not to succumb to them repeatedly.

  17. arya

    There are many planes of consciousness, right?

    So is it possible that each life corresponds to one plane, so that that particualr desire will be exhausted?

    For example, a celebrity in this life … does that mean he’s working on the vital plane, is that why karma is giving him riches/fame so he could exhaust vital desires?

    So once that’s done, next life he may take birth as a scholar or scientist so as to exhaust the desires of mental plane.

    And so on until supermind.

    Is this correct?

    1. Sandeep Post author

      No, each incarnation does not correspond to a plane, otherwise we would be done in seven lives. Even cats have nine lives !

      A human being has latent potential in many planes which gets exhibited in every incarnation.

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