Debate on psycho-Lamarckism (Experiments of Weismann, McDougall and similar, dog tail dogging)

By Wolfgang G. Gasser

Original discussion ("Lamarck and Darwin"): Comments to:

2015-01-31 #51

By Darwin123 in #38:

Lamarckian evolution has basically been disproved.

Lamarckism is only "disproved" by the untenable premise that genes contain the relevant information of an organism.

Darwinism however is disproved by empirical facts, the results of so-called adverse selection experiments:

"Tryon has bred rats selectively according to their ability on the California automatic maze, and, in a very carefully controlled experiment, has shown clearly that the offspring of 'bright' parents contain more 'brights' than 'dulls', and that the offspring of 'dulls' more 'dulls' than 'brights'. The interesting point here in connection with Lamarckian inheritance, however, is that both strains, 'dulls' as well as 'brights', became progressively better at learning this maze." (Nature, Feb. 4, 1939, Vol. 143, p.190)

And how do you explain William McDougall's experiment on the inheritance of acquired habits in rats?

2015-02-01  #64

By Mashuna in #58:

I believe that Jewish men have been conducting an experiment to test whether Lamarckian evolution is true, for a few thousand years now.

By Darwin123 in #60:

And Moslems. It is a shame that the foreskin hasn't disappeared over all this time, though.

2015-02-03 #75

By Fast Eddie B in #56:

"So the only reasonable explanation of McDougall's experiment seems to be the psychon thesis. All facts are consistent with this reincarnation theory."


The explanation just before the above conclusion:

"The inheritance of acquired habits cannot explain the increasing facility in learning of the control line rats which have no trained ancestors. The selection theory is disproved by the experiments with adverse selection. The fact that rats of other stocks did not improve in learning is not consistent with the theory of morphogenetic fields as proposed by Rupert Sheldrake." (Source)

 The control-line rats of generation 2 made lots of errors before learning the task going against their normal instinctive behavior. The error numbers of these seven rats are: 24, 30, 35, 36, 36, 37, and 56. In generation 20, two control-line rats knew instinctively the correct solution without committing a single error. Yet they had no trained ancestors, and no Darwinian selection had taken place.

Thus, everybody dealing with this experiment in an unprejudiced way has to subscribe to my above conclusion. And Darwinian selection as the main (or only) mechanism of biological evolution is simply disproved by adverse selection experiments:

The animals with the most successful strategies are not allowed to reproduce, but the animals with the least successful are allowed. And such experiments have shown that despite adverse selection the successful strategies propagate!

2015-02-09  #84

By turingtest in #77:

Also from your source:

"The facility in learning the task is transmitted not through genes but through reincarnation. For an improvement in learning, it is necessary that the souls of the offspring are the souls of the rats which have done the experiment earlier."

If the "successful strategies" propagated, but not, as you yourself say, in rats that were descendants of the "animals with the most successful strategies" (they were "not allowed to reproduce"), while your "psychon theory" of reincarnation requires them to be how is that theory supported? Whether the theory results in the "acquired habits" being so acquired through a Lamarckian process or one of reincarnation is irrelevant you've disproven both mechanisms by the same test.

No. Learned behavior has a tendency to become instinctive behavior by reincarnation. Therefore, it doesn't matter whether also the parents have learned the same behavior or not. See also.


By turingtest in #77:

In other words, you fiddled with the numbers to fit,

You can find the raw data I used for my table in table 2 of each Agar's second and third report. (Further reports: first, fourth).

"(2) McDougall found, as we have, that his rats showed a slight initial preference for the bright passage. In the later generations both of the main experiment, and of the experiment in which training was combined with adverse selection, this was turned into a pronounced preference of the dim passage." (First report, p. 209)

There was (artificial) selection of those rats with the strongest aversion to dim passages. There cannot be a doubt about the prediction of Darwinian Selection Theory: The aversion to dim passages should have increased in later generations. However, what happens in reality is the exact opposite: Despite selection for preference for bright passages, later generations develop an aversion to bright passages. So Darwinian Selection Theory is disproved, at least if one takes logical reasoning seriously.

2015-02-11  #89

By Nonpareil in #86:

Agar et al., Second Report, Page 1, Paragraph 1:

"The late Prof. McDougall's four 'Reports on a Lamarckian Experiment' are likely to become a classic of experimental biology, as being the most sustained attempt up to the present to demonstrate the reality of Lamarckian inheritance in a particular instance. Although, as will appear from this account of our own experiment, we do not believe that it will take its place in the history of biology as a successful attempt, we take this opportunity of acknowledging our appreciation of his nearly twenty years' devotion to this very laborious and exacting experiment."

Even your own sources point out, that this does not in any way actually stand as evidence for Lamarckian evolution.

McDougall's original experiment is a successful attempt insofar as McDougall found statistically relevant improvement in learning (even in case of adverse selection). In the first report Agar et al. write:

"His (McDougall's) principal evidence of Lamarckian inheritance is comprised in the following facts:

1) There has been a progressive - though irregular - decline in the average number of errors per generation; a very marked decline in the number of errors made by the best rat of each generation; and a less certain decline in the number of errors made by the worst rat." (See)


Agar et al. dismiss this statistically relevant decline in the number of errors by declaring that McDougall would (or could) have found the same improvement without training. They suggest three alternative explanations:

"(a) Selection: this however seems ruled out. Not only was the mortality in the main experiment very low, but McDougall has obtained an at least equally great improvement against strong adverse selection.

(b) A progressive unnoticed alteration in the experimental technique: this can probably be rejected also.

(c) A progressive change in the constitution of the rats due to factors other than the inheritance of the effects of training." (First Report, p.210)


As (a) and (b) can be excluded (also in the light of Agar's own results), only (c) remains as an explanation within the belief-system that genes somehow code for instinctive behavior, intelligence, preferences, aversions, phobias, and so on.

Within pandualist (i.e. not purely materialist) evolution, the results of Agar's control-group only confirm "environment continuity" as a fundamental principle of biological evolution, as the (trained) offspring of both the trained and the control line lived in the same environment with no discrimination of any sort.

We agree that purely materialist Lamarckism as an explanation is disproved by decreasing error numbers of rats without trained ancestors. Yet if one uses Occam's razor in a fully unprejudiced way, then psycho-Lamarckism is the most reasonable explanation: Transfer of acquired properties and habits to future generations by animal-souls and other psychons.

2015-02-15  #93

By wogoga in #84:

Learned behavior has a tendency to become instinctive behavior by reincarnation. Therefore, it doesn't matter whether also the parents have learned the same behavior or not.

By turingtest in #87:

... you're coming pretty close to reasoning in a circle; since "learned behavior... become[s] instinctive behavior by reincarnation" is the conclusion you need evidence for, you can't also support it by just asserting it as a "tendency."

The effect of becoming automatic resp. instinctive behavior can only be relevant if the behavior is repeated. Without repetition, an acquired skill (e.g. driving a car) will be lost again. Also, the more such an acquired skill has been repeated before disappearing again, the easier to relearn it. In this sense we can say: Learned behavior of animals and humans tends to become instinctive resp. automatic behavior.

According to materialist Darwinism, changes in instinctive behavior and acquired automatic skills of animals, learned in order to deal with constantly changing environments, must be "reinvented" in a completely different way on the molecular side (DNA). Otherwise what has been learned can never become innate behavior or an innate skill. Not to mention that, apart from materialist prejudices, there is no justification at all for the assumption that DNA is somehow capable of coding instinctive behavior, intelligence, and so on (see for instance).

A quote from Rat Learning and Morphic Resonance by Rupert Sheldrake:

"In mechanistic biology, a sharp distinction is drawn between innate and learned behaviour: the former is assumed to be 'genetically programmed' or 'coded' in the DNA, while the latter is supposed to result from physical and chemical changes in the nervous system."

2015-02-21 #102

By Reality Check in #91:

There are many experiments that have worked when run by the original team. What is important is that the experiments work when replicated by other teams. That is what is missing for these experiments dating from 1935.

"McDougall's experiment" and similar experiments have been performed and repeated over decades. In the table of my article I use the results of a replication, performed by Agar et al. in order to refute McDougall's results. Look at this table in an unprejudiced way!

By Reality Check in #91:

By citing these 80 year old experiments rather than their replications you are showing that these experiments are so flawed or obscure that no other scientist has bothered to do them again.

Scientists have stopped to replicate such experiments only after it had become clear that in case of careful and honest experiments, the results will continue to constitute an anomaly within the Darwinian belief system. Most scientists instinctively and/or consciously avoid experiments which threaten their beloved materialistic conception of the world.

If you think there are experiments disproving psycho-Lamarckism and supporting Darwinism, then please give some references.

By Reality Check in #91:

If they are flawed than you should not be citing them. If they are obscure then you are basically cherry picking by ignoring the enormous amount of evidence that Lamarckism does not exist.

What kind of "enormous amount of evidence that Lamarckism does not exist"?

The only experiment which is obviously flawed is the replication of McDougall's experiment by Crew. Crew became so desperate that he rendered all his rats extinct. Search for "Crew" in my article and in the one of Sheldrake.

2015-03-02  #122

By wogoga in #84:

Learned behavior has a tendency to become instinctive behavior by reincarnation.

By CapelDodger in #108:

Cross-species reincarnation invalidates that idea.

If you know an argument suggesting that "cross-species reincarnation", as a scientific hypothesis, makes as much sense as intra-species reincarnation, then please post this argument in the thread Reincarnation as a trivial scientific fact.

"Souls are considered physically real entities and evolutionary relatedness is considered a key property of evolution. The relatedness of your soul to the souls of your family is bigger than its relatedness to the souls of foreign cultures. So the probability that you will be reborn in your family is higher than that you reincarnate among persons you haven't been in contact with in former lives." (See)

2015-03-05  #137

Explaining Lamarckism by the hypothesis of evolution-by-reincarnation is apriori as justified, as explaining it by epigenetics. If you don't think so, then you should deal with the epistemology of Occam or Einstein. (If interested in what I mean, search for "epistemology" here.)

By Darwin123 in #129:

The rats in the main experiment and the control (i.e., adverse selection) were not in contact or in the same 'culture', at least not as shown in the article. The later generations were not in the same 'family' so far as was described in the article.

We are dealing with four different experiments with rats, all of which (with the exception of Crew) have shown strong improvement in learning a task in later generations:

         McDougall's original experiment (with sub-experiments such as adverse-selection)

         Repetition by Agar et al. with control lines

         Repetition by Crew (rendering all his rats extinct)

         Experiments of Tyron (inheritance of maze ability, also testing adverse-selection)

The main experiment of my article on McDougall's experiment is Agar's repetition (performed with the goal to refute McDougall's results):

"In the Agar experiment, rats which originated from a single mating were divided into a trained and a control line. In the trained line all rats were trained and the next generations have only trained ancestors. In the control line the parents of the next generation were left untrained. All rats were marked and bred together with no discrimination of any sort."

This means that all rats, both of the trained and the control line were closely related not only from an evolutionary but also from a kinship perspective. And you cannot deny that they lived in a very special environment (or "culture"), not existing normally in nature.

You may be skeptical about hypotheses such as reincarnation and "environment continuity". Yet it is a logical conclusion from these premises that relevant portions of later rat-generations consist of the souls of previous generations.

2015-03-08  #143

August Weismann's Experiments on the inheritance of mutilations

By MRC_Hans in #106:

Lamarckism is the thesis that, basically, if you cut the tails off enough generations of mice, tail-less mice would result. That thesis has been shown to be wrong.

We could also reduce Darwinism to absurdity in an analogous way:

Darwinism is the thesis that, basically, if you select in a breed the mice with the shortest tails over 5 generations, you will get mice with no tails (or with substantially smaller tails).

It is true that such an absurd caricature of "Lamarckism" has been shown to be wrong by August Weismann:

"Weismann conducted the experiment of removing the tails of 68 white mice, repeatedly over 5 generations, and reporting that no mice were born in consequence without a tail or even with a shorter tail."

Over 900 mice involved in Weismann's experiment, but tails were removed only to 68. In the first generation, tail-removing occurred only a few days before mating started. (There is some confusion about the number of generations involved in Weismann's experiment, as e.g. the first generation of mutilated mice alone gave rise to several "second generations", all obviously with normal tails).

If we cut off all tails after birth in a breed, then tails are still built up during embryonic development. The first effect of Lamarckism is that after some generations, the tail of an uncut mouse will not grow normally after birth, because the capacity of the tail to develop normally after birth is lost more and more in this breed.

In a second stage, tail-underdevelopment may already start at late embryonic development, and only in a third stage, mice with very underdeveloped tails may emerge (with or without the emergence of a corresponding gene-mutation).

There is a Lamarckian experiment, which is much more reasonable than the one of Weismann, namely the experiment of Brown Landone (see page 68 of his book):

"So I decided to carry on an experiment with white mice myself. Instead of cutting off their tails, I trained their tails to be more sensitive, to respond to action more quickly. I trained them for five generations and the mice of the sixth generation were born with tails more than twice as long as those of the first generation, and much larger; and the brain centers controlling the action of those tails were several times as large as similar brain centers in ordinary white mice."

If the magnitude of this Lamarckian effect is not exaggerated, then Brown Landone must (in opposition to Weismann) have killed the rats of his previous generations after birth (or training-start) of a new generation.

In any case, it would make sense to repeat Brown Landone's experiment, yet Darwinists avoid such experiments like the plague.

2015-03-26  #150

Dog Tail Docking

By Reality Check in #120:

* There are no observations that show that Lamarckism exists. We have been physically altering domestic animals for centuries and none of these physical alterations have been inherited, e.g. the docking of boxer tails and bobbing of ears.

I'm quite sure that a serious investigation would or will show that short tails and tail defects are more frequent in breeds where cutting tails has a long tradition. Quotes from your site:

"At least 17 dog breeds have naturally occurring bob tail lines."

"As a result, tail defects that docking proponents claim makes docking necessary in the first place are perpetuated in the breeds."

Interesting quote from Ancestral T-Box Mutation Is Present in Many, but Not All, Short-Tailed Dog Breeds:

"Tail docking is prohibited in many European countries, and the docked dogs cannot participate in official dog shows or trials unlike natural bobtails. The owner of the bobtailed dog needs a certificate from a veterinarian to prove the natural short tail to get access to shows."

Further quotes Ancestral T-Box Mutation Is Present in Many, but Not All, Short-Tailed Dog Breeds:

"Although the T gene mutation is present in many breeds, it does not explain all short tail phenotypes. Boston Terrier, English Bulldog, King Charles Spaniel, Miniature Schnauzer, Parson Russell Terrier, and Rottweiler breeds all have natural short-tailed dogs but the analyzed bobtails carried neither the known C189G T gene mutation nor the other novel causative mutations within the same gene. The short-tail phenotype includes either a complete lack of vertebrae or a short tail with variable length."

"The rare short-tailed Miniature Schnauzers, Parson Russell Terrier, and Rottweilers that were part of the study were all born from long-tailed parents, suggesting a recessive model, spontaneous developmental abnormality (congenital and not hereditary), or a sporadic mutation."

"Boston Terriers and English Bulldogs all either lack or have very short and kinky tails, indicating that the phenotype is fixed and has become part of the breed characteristics. The mode of inheritance has been suggested to be recessive."

A quote from

"In English bulldogs and all other dogs, tail docking is the practice of intentionally removing part of the tail through surgery. Tail docking is a controversial procedure. While some in the United States still perform the procedure, as of 2014, docking is banned in the United Kingdom and Australia."

So sum up, empirical facts related to the long tradition of cutting tails in dog breeding suggest a Lamarckian inheritance effect.

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