Talk:The Wonder Weeks

Plas0420
A small heads up: the single-purpose account Plas0420, who recently edited this page, is a self-admitted close relative of Plooij. On his Dutch wikipedia page, he explains that he's Marco Plas, who is "head of research" of the eponymous company "The Wonder Weeks", so he's clearly involved in this. Both personally and financially. On the Dutch wikipedia he received bans and warnings for, amongst other things, repeatedly removing text from other users from discussion pages and for threatening legal steps against other wikipedians  PizzaMan  ♨♨♨  19:52, 3 February 2018 (UTC)

NPOV
This article had a lot of problems. I think everything is now traced to appropriate secondary sources in the scientific literature, while still retaining the ephemeral interpretations by journalists for the sake of recording the controversy as historical fact.

Bn (talk) 01:36, 28 September 2019 (UTC)


 * I've flagged this as containing NPOV issues. The "three replications" you add - plus the criticism of de Weerth's work - are all from the same book edited by Plooj and ergo aren't peer-reviewed. That's hardly evidence of good or independent support at all. Another example: "Further corroboration comes from independent lines of investigation into periodicity of early childhood illness" - but then the paper cited is, again, by Plooij - surely if Plooij is the author it's not independent? Mvolz (talk) 19:26, 5 October 2019 (UTC)


 * There are some problems of fact in your objections. First, the book was edited by M. Heimann. Plooij is among the contributors, in all but one case together with co-authors. Secondly, even if he were the editor, it would not follow ("ergo" is your word) that there was no peer review of the book's chapters. In fact, there is no reason to suppose peer review was lacking. In my experience, Erlbaum does (or did) require peer review of research reports in a book like this, as is generally true of academic publishers. For example, Taylor & Francis, the parent of Erlbaum since 2006, is characterized in its WP article as publishing "peer-reviewed books and journals", an anambiguous statement of policy. Third, you say this does not constitute independent support. If by that you mean that the three replications of research by the Plooijs and others are not independent of Plooij, that independence is a function of who does it, with what subjects, and in what locations, and subsequently publishing the results in the same journal or book does not erase the fact that the research itself was independent. Independence is, after all, essential for replication, though this may have been forgotten in fields where replication is vanishingly rare.


 * But aside from that, what Wikipedia policy or guideline requires that RS must be peer-reviewed? WP:V clearly approves alternatives, even self-published works. A question about peer review bears on the validity of the reported research. That has nothing to do with NPOV. If you really believe RS must be peer reviewed than shouldn't you be asking for better citations rather than flagging for NPOV?


 * In particular, it would help NPOV if you could find a rejoinder or rebuttal by de Weerth or van Geert; I have not been able to find any. Alternatively, some readers might perceive insufficient coverage of research by a woman vs. that of a man. That issue can as justifiably be framed in terms of the decades of work by Hetty Plooij in relation to that of P. van Geert and his student. But if anything like this is your concern, you have not said so. You might have Undue Weight in mind, but the topic of the article is not a minority point of view relative to the mainstream view in a science, though that may have been a motivation of an academic quarrel reported in Dutch newspapers 22 years ago, the article is about a popular book for mothers of babies. But suppose the article really were about majority-minority views in a science. Do the research results represent a minority view or consensus? When I look over the 43 citations of the Heimann book reported by Google Scholar, I see no critical reviews or dismissive references. Instead, the work is cited neutrally (e.g. in work on the role of imitation in infants' development) or with approbation. A brief search found four additional citations that I will be happy to furnish here if you wish, e.g. from the Brazelton Touchpoints Center. So it appears that the consensus in the field accepts the research results that have been published in the Heimann book and elsewhere and builds further on them. I don't see a case for a criticism of undue weight.


 * Something gave you the feeling that the article needs work. I respect that, and I respectfully request that you take down the NPOV flag until you can state your concerns more clearly and directly.
 * Bn (talk) 14:08, 14 October 2019 (UTC)


 * I have now looked more deeply into de Weerth's publications and find that she has worked on relation of prenatal and postnatal parental stress to infant and child pathology, which would appear to concede point of controversy by overtly relinquishing the field of healthy infancy which is the purview of the topic book. On review today, I believe I have "reasonably fixed the issues" involved here and accordingly I will be so bold now as to remove the NPOV template.
 * Bn (talk) 10:40, 15 October 2019 (UTC)

Recent edits were not actually supported by the sources
On the Dutch wikipedia page on the book, a professor in the field (Van Geert) is quoted as stating that the theory of predictable growth moments deviates extremely (sic) from the common scientific knowledge on the subject (source). So i have my doubts with the direction this article took. Especially since the publisher of the book (Plas0420) tried very hard to manipulate the Dutch page. In the discussion on the Dutch page, we concluded that the claims that Plooij's research had been reproduced were not really substantiated by the sources provided by the publisher (and through him probably bu Plooij himself, since he's the son in law of Plooij). A summary of the Dutch talk page, where i looked at all the articles citing Plooij's articles (as of 2018):

'''The Temporal Relation between Regression and Transition Periods in Early Infancy (Sadurni M1, Pérez Burriel M, Plooij FX. Span J Psychol. 2010 May;13(1):112-26) '''

1 citation:


 * OUTLINING THE WINDOWS OF ACHIEVEMENT OF INTERSUBJECTIVE MILESTONES IN TYPICALLY DEVELOPING TODDLERS (Sadurní Brugué M1, Pérez Burriel M1. Infant Ment Health J. 2016 Jul;37(4):356-71. doi: 10.1002/imhj.21576. Epub 2016 Jun 27.)

Article by a co-author of the cited article, proposing a different theory of different growth spurts. The proposed growth spurts in this article have ranges that overlap, to the point where there are no predictable growth spurts. It's also published in a local Spanish journal with a low impact factor.

'''Hersenveranderingen en ‘sprongen’ in de eerste 20 levensmaanden en de invloed van de context op gedragsmaten van regressieperioden (Plooij, FX. Acta Neuropsychiatr. Volume 10, Issue 3 September 1998, pp. 63-66) '''

Only published in Dutch. 2 citations:


 * OUTLINING THE WINDOWS OF ACHIEVEMENT OF INTERSUBJECTIVE MILESTONES IN TYPICALLY DEVELOPING TODDLERS (see above)
 * Empirical indicators for regressions and sudden transitions in babies (By: van Geert, P; de Weerth, C; ACTA NEUROPSYCHIATRICA Volume: 10   Issue: 3   Pages: 67-73   Published: SEP 1998)

This article debunks Plooij's theories. A translated quote ''It has long been known that development milestones vary greatly from baby to baby. A model like Plooij's needs to be substatiated very thuroughly to be credible.''


 * This exemplifies the fundamental error of confounding phenotypic behavioral 'milestones' with the genotypic cognitive capacities that enable them. See above.

'''DISTINCT PERIODS OF MOTHER-INFANT CONFLICT IN NORMAL DEVELOPMENT - SOURCES OF PROGRESS AND GERMS OF PATHOLOGY (van de Rijt-Plooij HH1, Plooij FX. J Child Psychol Psychiatry. 1993 Feb;34(2):229-45.) '''

This is the single research on which Plooij's theory is based, with only 15 mothers and only with questionnaires.


 * As noted, the specific research in infant development has been replicated, and the 'theoretical' basis is much broader.

14 citations, but most not relevant. The relevant ones:


 * both articles mentioned above


 * Emotional instability as an indicator of strictly timed infantile developmental transitions (de Weerth, C; van Geert, P. BRITISH JOURNAL OF DEVELOPMENTAL PSYCHOLOGY  Volume: 16   Pages: 15-44   Part: 1   Published: MAR 1998)

This research was explicitly aimed at substantiating Plooij's claims. In short: "The results failed to support the 10-period pattern". Plooij tried to forbid her from publishing this article, after which he was eventually removed from his position as professor.


 * As noted, refuted in 2003, to which there has been no rejoinder.

'''DEVELOPMENTAL TRANSITIONS AS SUCCESSIVE REORGANIZATIONS OF A CONTROL HIERARCHY (By: PLOOIJ, FX; VANDERIJTPLOOIJ, HHC AMERICAN BEHAVIORAL SCIENTIST  Volume: 34   Issue: 1   Pages: 67-80   Published: SEP-OCT 1990) '''
 * the other articles don't go into Plooij's theory on growth jumps.

Sounds revelavnt, but it is chimpansee research rather than human.

'''Vulnerable periods during infancy: Hierarchically reorganized systems control, stress, and disease (FX Plooij, Ethology and Sociobiology Volume 10, Issue 5, July 1989, Pages 394-395) '''

Is on kids of 3+ so not relevant.

So, the current line of the WP on this book, that it's well proven, deviates quite a lot from what experts in the field say and what i found with a literature search. Again, in the light of manipulation of the Dutch pages by the publisher of the book, i'm a bit reluctant to let the page stand in it's current state. Your input please.


 * Wait a second. In 2008, when Plooij's son-in-law (and publisher) tried to manipulate the Dutch WP page on this book, he sent me a WP mail with a literature list which was quite obviously composed by Plooij himself. In the discussions on the Dutch WP page we went into most relevant articles that in no way supported Plooij's claims! As voiced by his son in law. This stinks. I'm assuming it's someone on behalf of Plooij or his son in law/publisher doing these edits. So i'm reverting the article back to before when these edits were made. Bn, if i'm mistaking please post on this talk page specific text fragments from your sources that actually support the claims they were supposed to support. PizzaMan  ♨♨♨  17:53, 10 December 2020 (UTC)


 * [Response from Bn on 21 February 2021 moved here 15 February 2024.]


 * [When I submitted this in 2021 I mistakenly placed it within the above post with date 10 December 2020, right after the first citation and the commentary ending with the words "with a low impact factor." This confused the record and made it difficult to see who said what. I have moved it here at the end of Pizzaman's 10 December 2020 post today, 15 February 2024. ]


 * Sadurní and Burriel discuss several perspectives on infant development and emphasize what they have in common, then they report evidence of 'spurts' coinciding well with the beginnings of the 'regression periods' reported by Plooij et al.


 * Their general conclusion (as presaged in the abstract):


 * In an early study, Sadurní and Rostan (2002) confirmed the presence of 8 such regression periods during the first year of life of 18 Catalan babies. Their 8 regression periods were comparable to the first 8 of the 10 regression periods found by Van de Rijt Plooij and Plooij. The aim of the present study is to see whether the regression periods that we found are temporally related to some transition. ... [W]e have found 8 transitions periods in the first year of life. We have also observed a temporal relation between the regressions periods found earlier and the transition periods reported here.


 * To paraphrase in summary form statements that are repeated in several places in the cited literature: Plooij and other researchers reporting these results clearly agree that the 'milestones' sought by developmental psychologists do indeed vary greatly, but 'milestones' are phenotypic behavioral achievements, whereas the underlying stages in the development of the brain are genetically determined cognitive capacities that enable these achievements. These genotypic developments are hidden from view, within the brain. It is for this reason that these researchers have inferred the timing from the earliest time at which representative behavioral achievements are observed in any infant. The generalization to all infants is justified on the basis of their common genetic endowment. The variation in the timing of behavioral manifestations is environmentally contingent, and many conditions may cause delay in development of a given skill or 'milestone'. The environment obviously includes the social environment (at issue here are 'intersubjective' milestones) and the physical environment more generally. See the comment on extrinsic stress, in the present text of this WP article. From the brain's point of view, the body is part of its environment, and strengths and deficiencies in corporeal development of behavioral capacities are also factors in the brain's environment which may cause overtly observable behavioral 'milestones' to be delayed to a variable extent after the cognitive capacities to support them are in fact in place.


 * "What develops are not the new behaviors, skills, or task accomplishments, which are manifestations of underlying processes after interaction with the environment, but the underlying processes themselves that lead to the learning" (Plooij 2003:188, with citations of independent corroboration of this view).
 * Bn (talk) 18:51, 21 February 2021 (UTC)
 * The other comments imported from the Dutch Wikipedia here also reflect significant misreadings of the cited texts. Rather than dive into the whackamole swamp of refuting each claim (I have pressing responsibilities as PI under NSF grant), I will only enter a note of caution about anything coming from the Dutch Wikipedia world. Non-Dutch readers should read Dutch Wikipedia. You will see that 59% of articles were created by bots, and articles have the least 'depth' by far of any language edition with more than a million articles and the least content per article. More tellingly, its users "described the atmosphere on the Dutch Wikipedia as quarrelsome and distrustful, with ego and stubbornness named as the premier causes of conflict. There is a small hardcore group of users in effective control. An ability to argue is deemed indispensable to be heard. New users are discouraged by moderators from joining discussions in the Dutch equivalent of the Village Pump." In my experience, Pizzaman has been importing this gladiatorial style to this talk page with a persistent 'my way or the highway' practice.
 * Note that what looks like a ping to my user page is not because my user name is Bn, not Bn: is not. I only noticed the renewed evisceration of this article because I came here for an easy way to grab a citation in proper form for inclusion in a multi-volume book that I am editing.
 * Comments from Andrew Garrett below are more responsible and I will respond. Bn (talk) 14:46, 16 February 2024 (UTC)

2601:18E:C480:4AD0:FCA5:57B4:1440:354 (talk) 22:16, 15 February 2024 (UTC)

Introduction
Does the first paragraph give undue weight to the single de Weerth study? It suggests that a single study could invalidate the claims of the book — when the arguments against it rely more on prevailing academic consensus. I suggest that a more general statement (perhaps from a source like https://www.nytimes.com/2020/04/15/parenting/baby/sleep-regression.html) noting that regression periods are not well supported within academia would be more appropriate. The de Weerth study is appropriately addressed in the controversy section. Adondai (talk) 01:12, 5 January 2021 (UTC)

I note the same source also states that Ploonijs employment contract was not renewed. This page states he was fired. Do other sources substantiate that he was fired? Adondai (talk) 03:04, 5 January 2021 (UTC)


 * It's a reliable source, namely a reputable Dutch newspaper. If i recall correctly, i saw other sources (Dutch newspapers) that confirmed it. US newspapers can in general be a little euphemistic in their reproduction of facts ;-) Even so, for a professor the difference is near irrelevant: it's very uncommon for the contract of a professor not to be renewed and besides, a temporary contract for 5 years doesn't really exist in Dutch law, except for (phd) students. The debate on his theory is one thing, but the fact that he got fired over the situation isn't controversial imho.
 * As for the De Weerth study: 1: it's one of the studies that set out to prove Plooij's theories and it failed to show the predictable groth jumps that Plooij found. 2: More importantly: we added a citation of an expert in the field who states that Plooij's theroy contradicts the broader body of research on baby development. What's more, 3: looking through all the articles that cited Plooij, i didn't find a single citation that actually contained research that confirmed his theories. As summarized above and discussed extensively on the Dutch talk page. So all three lines of logic point against his theory. And that's not counting the bias his publisher try to introduce on wikipedia (out of commercial motivations) and the fact that they threatened me personally with legal action if i didn't let them modify the Dutch WP as a fourth argument against his theory ;-) But i agree that a more general statement is better and changed the article accordingly. Thanks for providing the great source! (edit: made some edits to better respond to Adondai)  PizzaMan  ♨♨♨  10:50, 5 January 2021 (UTC)

What I liked about the NYT article is that it is fair about the value that parents find in the book (as a good summary of childhood development), even if some specific claims (10 defined regression periods) are disputed. I suggest that this page should reflect the reality that the book does provide useful information which contributes to its ongoing popularity. Adondai (talk) 23:33, 13 January 2021 (UTC)
 * I agree that that might better reflect a more accessible viewpoint as opposed to the scientific one i tend to represent. In that case we should imho balance that by also being less "scientific" in phrasing the criticism to this book. The regression periods are not "some specific claims" but the core theory around which the book is built (yes, we have a copy and i read it). And "disputed claims" means it's bullshit or we would have seen more evidence by now. In my view, parents finding value in the book is actually the book abusing the uncertainties of young parents about how to deal with their crying baby by offering a fake theory to give them comfort. There, now we need to phrase that a little more encyclopedically ;-) I'm probably not good at finding the right words since i may be a bit biased after the editor (Plooij's son in law) threatened me with legal action when i tried to keep him from turning the Dutch WP page into a PR page full of blatantly false claims. So please go ahead!  PizzaMan  ♨♨♨  21:09, 19 January 2021 (UTC)
 * @Adonai -- de Weerth did not replicate Plooij's investigation, because conditions were uncontrolled for extrinsic sources of stress to the infant, each occasion of which results in a cortisol spike, introducing chaotic noise into the data. This is documented in Chapters 3 and 5 of the Heimann volume, as well as in Plooij's rebuttal at the time. The claim that the book is scientifically unsound *must* refer to the science involved. Bn (talk) 16:43, 15 February 2024 (UTC)

Wholesale replacement of content not justified
It appears that Pizzaman did not read this article before deleting it, but rather relied upon his judgement of a different article on the same topic in the Dutch Wikipedia. Does it have to be pointed out that problems found on the Wikipedia for another language are irrelevant to articles in the English-language Wikipedia?

Let us examine the claims made here.
 * On the Dutch wikipedia page on the book, a professor in the field (Van Geert) is quoted as stating that the theory of predictable growth moments deviates extremely (sic) from the common scientific knowledge on the subject (source). So i have my doubts with the direction this article took.

This suggests that Pizzaman wishes to claim that this is a fringe theory. However, WP:Fringe is irrelevant here. This article is not about a theory, it is about a book. Even in an article about a theory, WP:Fringe is only concerned with undue weight.


 * A summary of the Dutch talk page, where i looked at all the articles citing Plooij's articles (as of 2018):

Is this a list of articles which cite Plooij's articles? It certainly is incomplete. If it is the list of Plooij's articles, it is quite incomplete. It omits most of the citations that were in the November 2020 version of this article, which Pizzaman deleted. The purpose of a citation is to enable readers to verify statements in an article. Citations to writings in languages other than English are of questionable value to readers of the English Wikipedia, certainly not when ample references in English are available.

For the record and for direct comparison, below is a list of the articles cited on the English-language page before Pizzaman obliterated it in December 2020.
 * de Weerth, C.; van Geert, P. (1998-03-01). "Emotional instability as an indicator of strictly timed infantile developmental transitions". British Journal of Developmental Psychology. 16 (1): 15–44. doi:10.1111/j.2044-835X.1998.tb00748.x. ISSN 2044-835X.
 * Hechler, C.; Borewicz, K.; Beijers, R.; Saccenti, E.; Riksen-Walraven, M.; Smidt, H.; de Weerth, C. (2019). "Association between Psychosocial Stress and Fecal Microbiota in Pregnant Women". Scientific Reports. 9 (1.4463): 4463. doi:10.1038/s41598-019-40434-8. PMC 6418257. PMID 30872645.
 * Heimann, Mikael, ed. (2003). Regression periods in human infancy. Mahwah, NJ: Erlbaum. ISBN 978-0805840988.
 * Horwich, R. H. (1974). "Regressive periods in primate behavioral development with reference to other mammals". Primates. 15 (2–3): 141–149. doi:10.1007/BF01742277.
 * Lindahl, L.; Heimann, M.; Ullstadius, E. (2003), "Occurrence of regressive periods in the normal development of Swedish infants", in Heimann, M. (ed.), Regression periods in human infancy, Mahwah, NJ: Erlbaum, pp. 41–55, ISBN 978-0805840988
 * Plas-Plooij, Xaviera; Plooij, Frans X.; Rijt-Plooij, Hetty van de (September 2019). The wonder weeks: A stress-free guide to your baby's behavior (6 ed.). New York: The Countryman Press (Norton). ISBN 978-1-68268-427-6.
 * Plooij, F. X. (2003), "The trilogy of mind", in Heimann, Mikael (ed.), Regression periods in human infancy, Mahwah, NJ: Erlbaum, pp. 185–205, ISBN 978-0-8058-4098-8
 * Plooij, F. X.; Rijt-Plooij, H. H. C. van de (2003), "The effects of sources of "noise" on direct observation measures of regression periods: Case studies of four infants' adaptations to special parental conditions.", in Heimann, M. (ed.), Regression periods in human infancy, Mahwah, NJ: Erlbaum, pp. 57–80, ISBN 978-0805840988
 * Plooij, F. X.; Rijt-Plooij, H. H. C. van de; Fischer, M.; Pusey, A. (2014). "Longitudinal recordings of the vocalizations of immature Gombe chimpanzees for developmental studies". Scientific Data. 1 (140025): 140025. doi:10.1038/sdata.2014.25. PMC 4322583. PMID 25977782.
 * Plooij, F. X.; Rijt-Plooij, H. H. C. van de; Helmers, R. (2003), "Multimodal distribution of SIDS and regression periods", in Heimann, M. (ed.), Regression periods in human infancy, Mahwah, NJ: Erlbaum, pp. 97–106, ISBN 0-8058-4098-2
 * Plooij, F. X.; Stelt, J. M. van der; Helmers, R. (2003), "Illness peaks during infancy and regression periods", in Heimann, M. (ed.), Regression periods in human infancy, Mahwah, NJ: Erlbaum, pp. 81–95, ISBN 0-8058-4098-2
 * Rijt-Plooij, H. H. C. van de; Plooij, F. X. (1987). "Growing independence, conflict and learning in mother-infant relations in free-ranging chimpanzees". Behaviour. 101 (1–3): 1–6. doi:10.1163/156853987X00378.
 * Rijt-Plooij, H. H. C. van de; Plooij, F. X. (1992), "Infantile regressions: Disorganization and the onset of transition periods", Journal of Reproductive and Infant Psychology, 10 (3): 129–149, doi:10.1080/02646839208403946
 * Rijt-Plooij, H. H. C. van de; Plooij, F. X. (1993), "Distinct periods of mother-infant conflict in normal development: Sources of progress and germs of pathology", Journal of Child Psychology and Psychiatry, 34 (2): 229–245, doi:10.1111/j.1469-7610.1993.tb00981.x, PMID 8444994
 * Rijt, Hetty van de; Plooij, Frans (2018). Oei, ik groei! De 10 sprongen in de mentale ontwikkeling van je baby (in Dutch). Amsterdam: Fontaine Uitgevers B.V. ISBN 9789059568488.
 * Rojas-Rocha, Xochitl (August 22, 2014). "Gombe chimpanzee calls available after 40-year wait". ScienceMag.org. American Association for the Advancement of Science. Retrieved September 28, 2019.
 * Sadurni, M.; Rostan, C. (2002). "Regression periods in infancy: A case study from Catalonia". Spanish Journal of Psychology. 5 (1): 36–44. doi:10.1017/S1138741600005813. PMID 12025364.
 * Sadurní, M.; Rostan, C. (2003), "Reflections on regression periods in the development of Catalan infants", in Heimann, Mikael (ed.), Regression periods in human infancy, Mahwah, NJ: Erlbaum, pp. 7–22, ISBN 0-8058-4098-2
 * Simons, Sterre S. H.; Zijlmans, Maartje A. C.; Cillessen, Antonius H. N.; de Weerth, Carolina (2019). "Maternal prenatal and early postnatal distress and child stress responses at age 6". Stress. 22 (6): 654–663. doi:10.1080/10253890.2019.1608945. PMID 31092104.
 * Simons, Sterre S.H.; Cillessen, Antonius H.N.; de Weerth, Carolina (2017). "Cortisol stress responses and children's behavioral functioning at school". Dev. Psychobiol. 59 (2): 217–224. doi:10.1002/dev.21484. PMC 5324537. PMID 27774583.
 * Woolmore, A.; Richer, J. (2003), "Detecting infant regression periods: weak signals in a noisy environment", in Heimann, M. (ed.), Regression periods in human infancy, Mahwah, NJ: Erlbaum, pp. 41–55, ISBN 978-0805840988


 * Van de Rijt-Plooij & Plooij (1993) is the single research on which Plooij's theory is based.

This is false on several grounds. More relevant than Van de Rijt-Plooij & Plooij (1993) is the following, which Pizzaman failed to list:
 * van de Rijt-Plooij, H., & Plooij, F. X. (1992). Infantile regressions: Disorganization and the onset of transition periods. Journal of Reproductive and Infant Psychology, 10, 129-149.


 * The proposed growth spurts in this article have ranges that overlap, to the point where there are no predictable growth spurts.

(The reference is to Sadurní & Burriel (2016).) This betrays a fundamental misunderstanding of what is claimed. The book makes clear that the timing is determined by development of the infant's brain, not by the mother's calendar. It would be naive not to expect variation as with all other aspects of biological development. Woolmore & Richer (2003) and others document the difficulties that must be carefully attended to,

De Weerth tested cortisol levels in saliva of four infants, taking this as indicative of stress, and looked for correlation with the predicted transition periods. However, these were in family situations in which the infants were under persistent or recurrent stress. Woolmore & Richer (2003) explains the importance of this fundamental methodological error. De Weert & van Geert (1998) was thoroughly debunked by Plooij & van de Rijt-Plooij (2003). So far as I can determine, that is the last state of the scientific controversy. If there has been a rejoinder to this, please cite it. I cannot find any.


 * Plooij was "removed from his position as professor".

This is a tendentious overstatement. As cited sources state, his contract came to an end. I enquired with a Dutch colleague, and she explained the funding and tenure of an endowed professor (bijzonder hoogleraar) in the Netherlands—a matter with which Pizzaman is presumably more familiar than I. However, Plooij's change of institutional affiliation is irrelevant to the actual scientific controversy, and the clearly intended innuendo about his standing as a researcher will be removed. As far as I can tell it seems to be a remote echo of someone's personal vendetta. Not only is it a materially irrelevant use of invalid ad hominem and ad verecundiam forms of argument, it is morally indefensible because the attacked person cannot defend himself in an article about a book which he co-authored and in which he has a material interest.


 * "I'm assuming it's someone on behalf of Plooij or his son in law/publisher doing these edits. So i'm reverting the article back to before when these edits were made. Bn, if i'm mistaking please post on this talk page specific text fragments from your sources that actually support the claims they were supposed to support."

Pizzaman, you are assuming that I have a conflict of interest (COI). This is a rather demeaning violation of the behavioral guideline to assume good faith.

Full disclosure, then. I have no connection to the book or the company that publishes it. My interest is in the underlying science, Perceptual Control Theory (PCT), with which I have been engaged for thirty years. Over that time, I have on rare occasion seen email exchanges between Frans Plooij and PCT researchers but have not had occasion to write to him myself, as the field that I bring to PCT is quite different, until I was preparing my chapter of The Interdisciplinary Handbook of Perceptual Control Theory (Elsevier 2020, Warren Mansell, Ed.). (A search of the email archives of The International Association for Perceptual Control Theory (IAPCT) indicates that direct intercommunication between the Plooijs and PCT researchers had begun in 1990, the earliest year archived, or perhaps somewhat prior.) I have met Plooij but once, at the 2019 IAPCT Conference (in Manchester, England), at which time I learned some new information about development of the cerebellum (in evolution and in human embryology and development) which was enlightening and useful for my own research interests.

I am also an interested reader and user of the book, have confirmed its findings with my own granddaughter, and have heard corroborative testimony from a good number of young parents who have put the book to the test of experience and have found it to be accurate and helpful, including my daughter and son-in-law and a score or so of their friends.

I trust that suffices for my bona fides. I will not stoop to ask you in turn whether you have some special connection to Paul van Geert, as for example having been his student. None of this ad hominem innuendo belongs in an encylopedia article about a book, and certainly is not in keeping with WP:GF.

Discussion of the disagreement about methods and results belongs on a new Wikipedia article about infant regression periods. There is no question that this is a notable topic. Antonius, Cillessen, de Weerth, Fischer, Heimann, Helmers, Horwich, Lindahl, Plooij, Pusey, Rojas-Rocha, Rostan, Sadurni, Simons, Stelt, Ullstadius, Woolmore, Zijlmans, and other researchers could all freely contribute to that article, without COI. I understand that others are now in process of writing this article. I may participate in editing it, if it seems to me appropriate.

In the present article about the book, all that is needed is a brief summary of the scientific issues in the controversy. Discussion of personnel conflicts drawn from gossipy newspaper articles has no place here, and is of questionable relevance to the separate article about scientific research, even in a section on controversy.

In consideration of all of this, I will now restore the article as of November 2020, and then proceed to edit it, removing the discussion of the personal conflicts and reducing the discussion of the scientific disagreements to an NPOV summary with a wikilink to the anticipated separate article. If you disagree with this, you will have to provide reasons more substantial than what we see here. Before making any further edits, provide your justification on this Talk page first. Bn (talk) 18:17, 16 February 2021 (UTC)


 * I had hoped that this time it'd be an improvement, but unfortunately I've had to tag NPOV again. I understand you believe passionately in PCT but Wikipedia is not a soap box. Mvolz (talk) 12:19, 18 February 2021 (UTC)


 * Mvolz, please explain how a description of the theoretical frame of reference of the book fails NPOV, and explicitly state your reasons for wanting to omit it. Please place your explanation in the section "Scientific frame of reference" below. Until you have properly justified a tag for NPOV, please remove it. If you decline without responding, then of course I or someone else will.
 * Bn (talk) 17:09, 18 February 2021 (UTC)
 * @Mvolz, you still have not responded to this. 'Passion' has nothing to do with it. It is a matter of fact that Plooij based his research in PCT, as a test of its prediction "that in the course of early ontogeny, a hierarchical organization emerges in the central nervous system that underlies the behavioral development of free-living chimpanzee babies and infants. ... we went on to observe and film human mothers and their infants in their home environment .... These studies clearly demonstrated that human babies, too, go through [such]... phases in a similar way. Each ... change enables babies to enter a new perceptual world." p. 15, 2017 edition. Elsewhere on this talk page I have quoted from scientific publications showing the basis in PCT more explicitly.
 * Plooij observed that prior to their work "such regression phases had been found by others in 12 other primate species and two lower mammalian species, indicating that this appears to be an old phenomenon, perhaps emerging during the very evolution of life on earth." (ibid.) He saw that PCT provided an explanation for the ontogeny of structure and function correlative with the emergence of perceptual/behavioral competencies in living things, which previously had been a regularly confirmed observation without explanation. His research added to the prior ethological findings first for primates and then extended them to humans and also constituted a test of that explanatory hypothesis.
 * This simple matter of fact is especially important to include because of the unfounded claims that the book has no basis in science. Such claims violate NPOV.
 * Claims that this work contradicts current consensus in the field and should on that account be disregarded also violates NPOV. Disagreement is normal in science, and it is well established that consensus in a field is a political and sociological consequence as much as it is a strictly scientific accomplishment. I think this is well enough known not to require me to invoke Popper, Kuhn, Feyerabend, and examples in the histories of particular sciences.
 * PCT predicts these regular stages of ontogeny. The statistical techniques of Paul van Geert do not, techniques such as fitting noisy statistical data to a logistic curve, resampling, and repeated random sampling ('Monte Carlo') (see Paul van Geert). This is why van Geert and his student (Plooij's graduate assistant) were perfectly happy with noisy data and took no care to remove confounding variables from the experimental/observational situation. Bn (talk) 14:21, 16 February 2024 (UTC)

New journalism
The NYT did a piece on this in 2020 - looks fairly thorough. Probably worth using as a jumping off point:


 * This newspaper piece by Jessica Wapner is referenced and cited. Bn (talk) 17:09, 18 February 2021 (UTC)

Scientific frame of reference
Mvolz says (above) that describing the theoretical background, explanatory framework, and scientific basis of the book violates NPOV. Cited RS clearly show that negative-feedback control theory as applied to ethology (von Uexküll and Kortlandt) and specifically as a general theory of behavior (Powers et al.) was the organizing theoretical framework for the research with mothers and infants which is the basis and justification of this book. It is what enables this book to propose practical advice for parents. What would be the motivation for omitting this objective fact about the book, and would not such a motivation violate NPOV? Bn (talk) 17:09, 18 February 2021 (UTC)


 * I said no such thing. Don't put words in my mouth. I said it was overall not NPOV, motivated by your passion for PCT. Mentioning PCT is fine. What isn't fine it that you have removed anything remotely critical and then made up - not cited - long explanations of why you personally think one paper is bad and is another is good. This is point of view pushing, motivated by your personal interest in this framework. If you remove the tag before it is addressed I will escalate this. Cheers! Mvolz (talk) 18:29, 18 February 2021 (UTC)


 * Forgive me for understanding your second sentence as an explanation of the first. Since you said nothing else about why you thought it was not neutral, I had nothing else to go on.


 * Please specify where I have quoted or interpreted the cited literature in a non-neutral way.
 * Bn (talk) 20:20, 18 February 2021 (UTC)
 * @Mvolz, I am still waiting for your reply to the above. Please specify where I have quoted or interpreted the cited literature in a non-neutral way. I will be happy to fix those places, or you can and I am willing to help.
 * Why de Weerth's paper is 'bad' (your word, not mine) is that in a crucial way she did not in fact replicate Plooij's research, so claims that she 'refuted' it are simply false. This is not what I "personally think", as you say, it is well documented in cited sources. She collected data on cortisol spikes as indicators of stress in the infants in her study. To collect data on stress that is due to reorganization as the brain grows and develops a new order or level of the perceptual hierarchy it is necessary to control the environmental conditions so as to minimize extrinsic sources of stress which introduce unpredictable noise into the data. Elimination of confounding variables is elementary in any scientific investigation. The critiques of de Weerth's dissertation work, and indeed her publication itself, document clearly that her subjects did not satisfy this fundamental requirement. The result was that her data satisfied the expectation which her mentor and dissertation supervisor explicitly stated in numerous places, that it should be chaotic with no obvious 'leaps'. As Woolmore & Richer (2003) conclude,
 * Just as any study that finds regression periods must be carefully scrutinized to ensure spurious synchrony across babies has not been read into the data, so studies that fail to find regression periods must be carefully scrutinized to ensure they have not simply failed to see through the "noise" in their data, such that they have mistaken their own failure to find the phenomenon for the phenomenon's nonexistence.
 * Why collect data on intrinsic stresses within the developing infant, controlling carefully to minimize extrinsic sources of stress? This is because the point of the research is to test the premise that the developing infant brain grows in regular stages, both in size and in cognitive competencies, and that this has behavioral consequences which occasion uncertainty and stress. In his publications, Plooij stated that the premise for his work was to put those predictions to empirical test, beginning with the work with primates in the 1970s and 1980s.
 * Paul Van Geert was Carolina de Weerth's teacher and dissertation supervisor. In addition to his explicit statements (noted above), even a simple survey of the titles of his publications listed on that page clearly state his intellectual and theoretical expectation that child development is chaotic rather than ordered by emergence of successive levels of the perceptual hierarchy over time. De Weert's results were consistent with that expectation, as he stated in the Trouw article. In my estimation this conflict was unfortunate and unnecessary. PCT is a dynamic systems theory, and random or chaotic paths of development have an inherent place in it, in the mechanisms for forming and modifying connections and parameters of negative-feedback control systems within living things.
 * In any search for mainstream views about infant cognitive development, the views identified are those of Piaget, Kohlberg, and Vygotsky. Start your search with the WP article Infant cognitive development. The present article should not claim or imply that van Geert's views represent consensus in the field. Bn (talk) 19:36, 15 February 2024 (UTC)


 * To further enhance NPOV I have added information about de Weerth's and van Geert's theoretical frame of reference. It is not relevant to the book, but it does appear to be the basis of the controversy. Discussion of conflicting scientific assumptions, methods, and predictions belongs in an article about the science, or perhaps in two articles. I have not found an article about the application of chaos theory and dynamical systems theory to psychology, but there is a section in the article on dynamical systems theory.


 * On 5 October 2019 you tagged this article for NPOV giving reasons that turned out to be false. A week plus later, on 14 October 2019, I said "Something gave you the feeling that the article needs work. I respect that, and I respectfully request that you take down the NPOV flag until you can state your concerns more clearly and directly." You never responded.


 * There are three conditions for removing the NPOV template. Two of them are:


 * 2. It is not clear what the neutrality issue is, and no satisfactory explanation has been given.
 * 3. In the absence of any discussion, or if the discussion has become dormant.


 * Both of these conditions having been met, I removed the template on 15 October 2019. The article has remained accepted until Pizzaman reverted it more than a year later (10 December 2020).


 * You are now doing the same thing as you did in October 2019, NPOV tagging with no specification of what passages you perceive to be non-neutral.


 * Both you and Pizzaman have presumed bad faith and conflict of interest on my part. My aim has been and is to present this from a neutral point of view. I believe I have done so. You'll have to point out what the problem is, because I'm not seeing it. I can't fix what (to my eye) isn't broken.


 * Perhaps you are researching the cited literature. If so, please so indicate here. If there is no response, I will remove the template per the same two conditions for removal, listed above. You said that you would escalate the matter if I did so, as if that were a threat that I should fear. I would welcome participation of editors who are helpful maintaining NPOV.
 * Bn (talk) 17:39, 19 February 2021 (UTC)

Scientific confirmation of Plooij's theory
De Weerth's conclusion "was immediately disputed". That's a bit misleading as the quoted source is actually Plooij himself, who was already entrenched in his theory and the profit he was making off the book. If Plooij was the only one who disputed De Weerth's findings, her findings were probably in line with the scientific consensus.

"The findings of Plooij and his colleagues have been replicated by three independent research groups" Please quote the actual scientific publications, rather than repeatetly referring to the same book, so we can actually verify them. Plooij's son in law referred to the same book, but wasn't able to refer to the actual peer-reviewed publications that were discussed in the book, i'm guessing because he didn't even possess the book he quoted. Considering how controversial the findings of these research groups seem to be, a book (which is not peer-reviewed) just won't do as a reference. We need to see references to the original research publications in peer-reviewed journals. From my own literature search, these didn't seem to exist.

As for the Sadurni paper, the only publication on the subject to ever point in the direction of support for Plooij's theory: first of all, Sadurni published together with Plooij, so it's not really a verification by an independent group. Moreover, it actually proposes a different theory than Plooij's, namely nine "Developmental Transitions of Intersubjectivity" rather than Plooij's ten growth spurts. Most importantly, if you look at the data in this article, there's so much overlap in the "developmental transitions" that it's hard to mantain this is a clear support for Plooij's theory of predictable growth spurts. The summary of the article doesn't properly summarize it's actual findings. Note that this article is only published in a local Spanish journal with an impact factor of only 1.6. If that's the best source supporting Plooij's theory, the basis for considering his theory generally accepted looks rather bleak.

Also note that the commercial success of The Wonder Weeks is based on the predictability of the growth spurts. This is not a straw man, it's the core theory around which the book is built. And it's the part that's not based in on reliable sources. For example, the book starts with a calendar in the book which you can use for when to expect the next growth spurt of your baby, and there's even a companion app where you can enter your baby's birthdat and see exactly when it'll have growth spurts as being precisely predictable. Posing that there are growth spurts, but their timing is random is actually saying the growth spurts are not predictable. That contradicts, rather than supports the essence of The Wonder Weeks.

In the Dutch version of the WP article i quoted an expert on the subject, Paul van Geert, who responded thus to De Weerth's findings the there were no predictable growth spurts: "The findings weren't remarkable. Plooij's book deviated extremely from previous research into baby development. Growth spurts had previously been described, but not as much as Plooij found and not as predictable. Not all advise in the book is controversial. But parents better not take the advice about all those growth spurts seriously... It's purely chance if their child fits Plooij's pattern." quote.

As for Plooij's contract not being prolonged, there was more than just the the contract ending naturally and Plooij leaving with the respect of his colleagues. Here's a quote from the rector magnificus of his university (about Plooij falsely still calling himself professor): "He's misrepresenting the facts. This rubs off on Plooij, not on us... Those who still do business with Plooij must have heard about all the commotion surrounding his book... Apparently he still thinks he's worth the title of professor." quote

In summary, if you want to paint a picture of Plooij basing his book on a scientifically established theory, i expect publications by multiple groups in peer-reviewed journals, preferably some with a serious impact factor. These should be summarized by review papers, quoting Plooij, summarizing how this theory is a thing. When i did a search a few years ago of all the reasearch quoting Plooij, i found nothing of the sort. Only one paper in a marginal local Spanish journal and very few citations at all for the few publications Plooij produced as a scientist. Weighing that against the expert quote above, it's really hard to present Plooij's theory as being in line with the scientific consensus.

 PizzaMan  ♨♨♨  22:39, 26 February 2021 (UTC)


 * Since there's no response yet, i've editet the article. I tried to leave as much of Bn's stuff in, but without the misquotations, dubious references and promotional-sounding phrasing. The paragraph of "theoretical basis" was a replication of the article on perceptual control theory, which is best expanded upon in that article imho. The claims paragraph is otherwise clear enough on what the book is about. Perhaps we could add a single sentence explaining PCT, but for more info on it the hyperlink will do. When reading the book, it emphasizes the predictable growth spurts, rather than PCT. The controversy section was way too biased imho. I reverted it, but added above quote on the topic and the NY Times quote in the lead. Considering this is apparently controversial, it's probably safest to stick to quotes from reliable newspapers on the subject or articles in peer-reviewed journals, rather than adding stuff that risks being personal interpretation of the sources. PizzaMan  ♨♨♨  23:00, 1 March 2021 (UTC)


 * I have reverted these changes with a renewed appeal to reach consensus here first. Please see my note on your user talk page. Be patient. More responses will be forthcoming. You and I are not the only contributors. Bn (talk) 12:17, 2 March 2021 (UTC)
 * Are you aware that you're the one who started out with deleting literal quotes by reliable sources such as the New York Times, to substitute them with references that spell out an opposite narrative but that mostly point to a single book, which is near impossible to verify and not actual underlying studies from peer-reviewed journals? In that context it's perhaps a bit one-sided to accuse me of prejudice. My primary prejudice is that i want to stick to summarizing reliable sources. Could you please respond to the actual issues i raise here about your sources and your interpretations in stead of attacking me as a person on my talk page?  PizzaMan  ♨♨♨  18:57, 2 March 2021 (UTC)
 * Your preferred quotation from the NYT is neither a conclusion nor neutral. It is as follows:
 * A New York times article concludes: "experts (and parents) agree that sleep patterns can vary wildly throughout a baby’s first two years, no rigorous data support the notion that nap and nighttime changes happen at predetermined times or are linked to specific developmental milestones." 
 * 'Sleep patterns and 'sleep regressions' are not the topic of the book and dwelling on them reflects a misunderstanding by the reporter. This passage is near the beginning of the NYT article, not a conclusion. Near the end of the article, and therefore more fairly to be considered the author's summation or conclusion, is this passage which refers to the actual subject matter:
 * [T]imed leaps may be real, but the evidence hasn’t proven if or in what capacity they exist. Neurologists are just beginning to understand brain patterns during the first two years of life. “We really are at the infancy of infant brain knowledge,” said Dr. Hirsh-Pasek, the psychologist at Temple University. Some pediatricians, though, believe Dr. Plooij’s theory is correct. Dr. Pamela Hops, M.D., a pediatrician in New York City, said that during her 20 years of practice, she has anecdotally seen and heard about changes in babies that perfectly align with the 10 leaps Dr. Plooij described. “I think he’s spot on,” said Dr. Hops, “shockingly so.”
 * I would be happy to include that. Bn (talk) 17:02, 15 February 2024 (UTC)
 * [The history of my Sandbox shows that this reply has been hanging fallow there since March 2021. Demands with higher priority and/or higher urgency took me away from any concern with this.]
 * Pizzaman: De Weerth's conclusion "was immediately disputed". That's a bit misleading as the quoted source is actually Plooij himself, who was already entrenched in his theory and the profit he was making off the book. If Plooij was the only one who disputed De Weerth's findings, her findings were probably in line with the scientific consensus.
 * Plooij was not the only one who disputed De Weerth's findings. Woolmore and Richer (2003) did too..
 * It is a simple statement of fact. The character of that fact is a matter of science. The evidence, argumentation, and conclusions presented in Your characterization that it was entirely motivated by commercial interest is an ad hominem insinuation that seems out of keeping with Plooij's documented long career as a scientist. This of course would not be the first instance in the history of science and mathematics--Hilbert and Brouwer in mathematics, for example. This could be relevant in an article about the science. This is not a biography of Plooij. Bn (talk) 19:28, 1 March 2021 (UTC)
 * Pizzaman: "The findings of Plooij and his colleagues have been replicated by three independent research groups"
 * Please quote the actual scientific publications, rather than repeatetly referring to the same book, so we can actually verify them. Plooij's son in law referred to the same book, but wasn't able to refer to the actual peer-reviewed publications that were discussed in the book, i'm guessing because he didn't even possess the book he quoted. Considering how controversial the findings of these research groups seem to be, a book (which is not peer-reviewed) just won't do as a reference. We need to see references to the original research publications in peer-reviewed journals. From my own literature search, these didn't seem to exist.
 * This is a collection of papers presented at a conference, an entirely usual and accepted way of publishing in science. Further, one cannot say that such books per definition are not peer-reviewed. Good publishers have peer review as a standard policy. Anecdotally, that has been my experience. You acknowledge that the replication study of Sadurni and Rostan (2002) was published in a peer-reviewed journal.
 * Pizzaman: As for the Sadurni paper, the only publication on the subject to ever point in the direction of support for Plooij's theory: first of all, Sadurni published together with Plooij, so it's not really a verification by an independent group.
 * This is a very strange attribution of a kind of 'guilt by association'. Nonsense.
 * Pizzaman: Moreover, it actually proposes a different theory than Plooij's, namely nine "Developmental Transitions of Intersubjectivity" rather than Plooij's ten growth spurts. Most importantly, if you look at the data in this article, there's so much overlap in the "developmental transitions" that it's hard to mantain this is a clear support for Plooij's theory of predictable growth spurts. The summary of the article doesn't properly summarize it's actual findings. Note that this article is only published in a local Spanish journal with an impact factor of only 1.6. Also note that the commercial success of The Wonder Weeks is based on the predictability of the growth spurts. Posing that there are grwoth spurts, but their timing is random, is actually saying the growth spurts are not predictable. That contradicts, rather than supports the theory as laid out in The Wonder Weeks.
 * There is a mixup of papers here. This work mentioned here has nothing to do with the replications studies and was not published with Plooij and reported independent research. It concerns the following papers published in 2014 and 2016: In contrast, the following two papers concern the replication studies: and.
 * Publications show that later Plooij and Sadurni worked together on the temporal relation between regression periods and clusters of new skills following the regression periods. 'Intersubjective milestones' are behavioral observations, not ontogenic stages of development. They evince ability to perceive (and control perceptions of) (1) dyadic person-to-person relationships, (2) triadic person-person-object relationships, and (3) perceptions of moral value or consequence of dyadic and triadic relationships. These are called primary, secondary, and tertiary intersubjectivity. The last was proposed by Trevarthen, who contributed to the conference and the Heimann volume reporting its proceedings. The temporal relations of the behavioral manifestations to the underlying ontogenic developmental changes is of obvious interest, and that is what Plooij and Sadurni investigated.
 * Pizzaman: In the Dutch version of the WP article i quoted an expert on the subject, Paul van Geert, who responded thus to De Weerth's findings the there were no predictable growth spurts: "The findings weren't remarkable. Plooij's book deviated extremely from previous research into baby development. Growth spurts had previously been described, but not as much as Plooij found and not as predictable. Not all advise in the book is controversial. But parents better not take the advice about all those growth spurts seriously... It's purely chance if their child fits Plooij's pattern." quote.
 * Paul van Geert is obviously not neutral in the matter, and though he deserves a voice he cannot be cited as exclusive authority for NPOV. In the quote, he ignores the fact that De Weerth's conclusion that there were no predictable 'growth spurts' was actually not supported by her data. Woolmore and Richer (2003) concluded that "studies that fail to find regression periods must be carefully scrutinized to ensure that they have not simply failed to see through the 'noise' in their data, such that they have mistaken their own failure to find the phenomenon for the phenomenon's nonexistence." In we can read on page 75: De Weerth and Van Geert (1998) "failed to report and take into account a number of environmental, parental circumstances, or sources of 'noise' in their data. .... Notwithstanding much oral and written debate since 1995  , in which the sources of noise were clearly spelled out, De Weerth and Van Geert kept insisting that "the differences in results are most unlikely to lie with the subjects which participated in the study" and that "strict selection procedures ... should guarantee that the infants are an adequate representation of a normal population (p.34). However small the chances are that three out of four families live under special circumstances, the fact is they did. This can not only be shown to be true with the help of the weekly questionnaire and interview data. Also De Weerth and Van Geert's own analyses of the observational data support it. For instance, the rigid sleeping, contact, and feeding schedules of mother-infant dyads F and J show up in the fact that infants F and J spent significantly less time in physical contact with their mothers than infants E and S ." Apart from the fact that the mother-infant contact and distance regulation could not be observed properly in these two mother infant pairs because the rigid schedules prevented the infant to restore contact with the mother, a third mother admitted halfway the study that she was depressed : "in her weekly interviews halfway through the first year after birth, the mother of infant S stated that she was depressed from birth onward and had been receiving therapy long before birth. Finally, she felt so troubled that she applied for renewed therapy at the department of psychiatry of the university hospital. In the interviews and the questionnaires this mother reported to feel depressed, overstrung, and all sorts of phobias (e.g., the fear to be alone, open the door, pick up the phone, and/or go into the street). She had nightmares, sleepwalked, hyperventilated, had various physical complaints, diarrhea, bad appetite for food, and so on. The mother of infant S realized the effect of all this on her infant and expressed the fear that her infant would be placed out of the home." Then Plooij and Van de Rijt-Plooij review the abundant evidence in the literature of major effects of parent's postpartum depression on the infant and the parent-infant interaction patterns. And it were the direct observation measures of these interaction patterns that de Weerth's study was all about. Reading all this, it seems the weight that you have given to the quote of Paul van Geert is not justified.
 * Pizzaman: for Plooij's contract not being prolonged, there was more than just the the contract ending naturally and Plooij leaving with the respect of his colleagues. Here's a quote from the rector magnificus of his university (about Plooij falsely still calling himself professor): "He's misrepresenting the facts. This rubs off on Plooij, not on us... Those who still do business with Plooij must have heard about all the commotion surrounding his book... Apparently he still thinks he's worth the title of professor." quote
 * this is not relevant to the discussion about the content of the research. Many a scientist's undisputed achievements would be erased if irascibility were sufficient cause, which is the silliness that you are claiming here. Isaac Newton for starters.
 * Plooij: In summary, if you want to paint a picture of Plooij basing his book on a scientifically established theory, i expect publications by multiple groups in peer-reviewed journals, preferably some with a serious impact factor. These should be summarized by review papers, quoting Plooij, summarizing how this theory is a thing. When i did a search a few years ago of all the reasearch quoting Plooij, i found nothing of the sort. Only one paper in a marginal local Spanish journal and very few citations at all for the few publications Plooij produced as a scientist. Weighing that against the expert quote above, it's really hard to present Plooij's theory as being in line with the scientific consensus.
 * Your requirement for "a scientifically established theory" is a Notability challenge that you might pose for the Perceptual Control Theory article. Good luck with that. It has no place here. Furthermore, it may reflect fundamental confusion about the nature of science. Work in science does not have to be carried out within the dominant paradigm in order to qualify as scientific.
 * The crisis in psychology and other disciplines that the majority of scientifically established theories published in peer-reviewed top journals cannot be replicated is well known. One of the remedies for resolving this crisis is replication studies. These are rare so far. And yet, three independent research groups have replicated the work of Van de Rijt-Plooij and Plooij : "all three studies come up with similar conclusions in that they favor van de Rijt-Plooij and Plooij's hypothesis."
 * Bn (talk) 15:37, 16 February 2024 (UTC)
 * The above has been lying fallow and unnoticed in my Sandbox since March 2021, according to its history. Bn (talk) 15:40, 16 February 2024 (UTC)

Toward NPOV consensus
I apologize for the delay. A number of personal and professional responsibilities have supervened.

Rather than be disputatious, let us focus on the facts to be documented. Some facts you do not dispute, some you do, some are not included which you feel should be, some may be included which you or I or perhaps both of us feel should not be, and for some facts, I am uncertain whether you dispute them or not.

A. Facts that you do not dispute:
 * 1) That De Weerth proposed to replicate Plooij's research, and claimed that she did.
 * 2) The facts stated in the brief summary of her methods
 * 3) The facts stated in the brief summary of her results.
 * 4) That she presented her methods and results in a 1998 dissertation.
 * 5) That van Geert was her dissertation supervisor.
 * 6) That in 1998 she published her methods and results jointly with Van Geert in  British Journal of Developmental Psychology, 16, 15-44.
 * 7) That in 1998 in Acta Neuropsychiatrica, 10(3), 63-66 Plooij published a summary of his work and critical discussion of De Weerth's work.
 * 8) That in 1998 in Acta Neuropsychiatrica 10 (3): 67–73 de Weerth and van Geert jointly published her methods and results a response to Plooij's article in Acta Neuropsychiatrica, 10(3), 63-66.
 * 9) That in 1998 In Acta Neuropsychiatrica 10 (3): 74–77) Plooij published a reply to van Geert and de Weerth's response in Acta Neuropsychiatrica 10 (3): 67–73.
 * 10) That in 2002 in Infant Behavior and Development de Weerth and van Geert jointly published cortisol data for the same four infants.

B. Facts that you dispute:
 * 1) That Plooij's two papers in Acta Neuropsychiatrica 10 (3): 63-66 and 74–77 refuted van Geert and de Weerth's claims to have replicated Plooij's research with contrary results. In Acta Neuropsychiatrica 10 (3): 74–77) (also 1998, obviously) Plooij published a refutation of van Geert and de Weerth's Acta Neuropsychiatrica paper (and her dissertation). I used the more neutral word "disputed" rather than "refuted". I said "immediately disputed" because Plooij's last Acta Neuropsychiatrica paper is in the same journal issue, beginning on the very next page. I note in passing that the journal editor clearly did not see Plooij's work as unworthy.
 * 2) That reports of replication by three independent research groups were presented at a conference in 1997 and published in 2003. As you can see in the PDF image of the book (which is not that difficult to find), these were previously presented in a symposium held at Göteborg University Sweden on October 10—11, 1997 (The First Research Conference on Regression Periods in Early Infancy).
 * 3) That de Weerth and van Geert did not replicate Plooij's research methodology. Plooij, Woolman, and others demonstrated how their selection of subjects introduced noise in their data so that they could not legitimately be contrasted with data from a properly designed study.
 * 4) That the research reported in these papers is 'real science' and that they are appropriate RS citations.
 * 5) That the Heimann book was peer reviewed.
 * 6) That de Weerth's results are controversial. (An exchange of papers and refutations is virtually the very definition of academic controversy.)
 * 7) That de Weerth's results have not been replicated in the given research methodology that she claimed to replicate.
 * 8) That the theoretical framework of Plooij's research is Perceptual Control Theory (PCT).
 * 9) That PCT predicts and explains the successive stages of growth and reorganization that the four independent research groups found.
 * 10) That PCT is 'real science'.

C. Facts of uncertain status as to whether or not you dispute them:
 * 1) That neither de Weerth nor van Geert has published a rejoinder to the 2003 rebuttals by Heimann, Woolman, et al.
 * 2) That the selection as subjects of mother-infant dyads in happy, harmonious families free from extrinsic sources of stress is an essential prerequisite to replication of this kind of research, leaving pathology for future research.
 * 3) That a 'child-following' mother-infant relationship is is an essential prerequisite to replication of this kind of research.
 * 4) That van Geert has intellectual and professional commitments to the application of dynamic systems theory to modeling infant development.
 * 5) That results that are not chaotic, with wide individual variation, conflict with predictions of dynamic systems theoretic models of infant development.
 * 6) That Mende et al (1990)  found independent evidence supporting the regression periods found by Van de Rijt-Plooij and Plooij (1992). These authors analyzed infant cries and, using a tool that they developed for early diagnosis of CNS disorders, they discovered that infants sometimes  produce  instead of normal phonations a special sound which they called "cerebral peep" (not to be confused with cerebral Positive end-expiratory pressure, PEEP). This different phonation was typical for regression periods in the babies' vocalization development, especially just before the first manifestation of a new level of prespeech performance. The timing was at the same ages as the regression periods found by van de Rijt-Plooij and Plooij (1992). These periods of regression are external signs of reorganisation processes in the brain and of inauguration of new regulation by superimposed brain centers. Further discussion in, e.g. "we strongly recommend an inclusion of structural developmental data before further testing any hypothesis" (p. 475).

D. Facts that are presently not included:
 * 1) That Plooij objected to her methods and said they did not replicate his research.
 * 2) That it is said that Plooij tried to block de Weerth and van Geert from publication.
 * 3) That Plooij denies this (in the NYT article).
 * 4) That van Geert called Plooij "indecent".
 * 5) That Plooij had a temporary, contractual professorship of a sort that is not found in every country. A colleague in the Netherlands (who is unrelated to Plooij) says that he appears to have been a special professor (bijzonder hoogleraar). "Dutch universities ... appoint professors occupying an endowed chair (Dutch: "bijzonder hoogleraar", literally "special professor"), often on a part-time basis. Special professors usually have their main employment somewhere else, often in industry or at a research institute or University elsewhere.... The special professor (bijzonder hoogleraar) does not get paid by the university, but receives a salary from an external organization, such as a company, an organization or a fund. Special (endowed) professors sometimes provide lectures or do research on special topics associated with their main employment. They also often supervise graduate students who may do their research at the place of the professor's main employment." Academic_ranks_in_the_Netherlands
 * 6) That the three replication studies were published in a peer-reviewed volume resulting from a conference (Heimann 2003) and one of them has also been published in a peer-reviewed journal. Unidentified IP 78.82.82.235 framed this fact pejoratively as follows: "Two of the three replication studies has [sic] not been published in peer-reviewed journals."
 * 7) "Mikael Heimann, professor emeritus at Linköping University, was responsible for the study conducted in Sweden. He says that the research done on the subject is very important, but difficult to define. There is agreement on certain periods in an infant's first year, but there is probably no total agreement in the science on all the phases that Plooij identified and which we also then partially identified, says Mikael Heimann to DN, while asking for more research on the subject." ; PDF (Swedish) at https://www.dropbox.com/s/vjy5f9a2r6getsf/%E2%80%9DWonder%20weeks%E2%80%9D%20%E2%80%93%20forskningen%20bakom%20appen%20ifr%C3%A5gas%C3%A4tts%20-%20DN.SE.pdf?dl=0; PDF (English translation) at https://www.dropbox.com/s/ig086mx0x9s45pd/Can%20an%20app%20provide%20answers%20to%20how%20your%20infants%20develop.pdf?dl=0
 * 8) Mikael Heimann said: "there are still many unanswered questions. But this fact does not preclude a conclusion saying, based on our current evidence, that regression periods ought to be considered as a real phenomenon and dealt with accordingly whenever developmental processes in infancy are discussed." (Heimann 2003:x). "Because brain changes are not directly observable and the emergence of new skills shows tremendous individual differences ... the age-specific regression periods found by the Dutch team ... stand out as unique hallmarks to direct a study of developmental change." (Heimann 2003:3) "It is my view that the observations presented throughout the book provide good support for the fact that up to 10 regression periods might exist during the first 15 months of life." (Heimann 2003:4)

E. Facts that I question

Bn (talk) 19:50, 4 April 2021 (UTC)
 * 1) That Mikael Heimann, editor of the book that summarizes the replications of Plooij's original study, said in an interview 2019 that "in the science, there is no agreement about the phases that Plooij has defined."  . Unidentified IP 78.82.82.235 referred to the replication studies as "attempts to replicate", an unsupported implication that these replications failed. Given the continuance of this lack of neutrality, it is essential to see the context of this quotation and verify the translation from Swedish. The page is behind a paywall. I have asked a Swedish friend for assistance.


 * Here you can find the article from the Swedish newspaper as a .pdf file: https://www.dropbox.com/s/vjy5f9a2r6getsf/%E2%80%9DWonder%20weeks%E2%80%9D%20%E2%80%93%20forskningen%20bakom%20appen%20ifr%C3%A5gas%C3%A4tts%20-%20DN.SE.pdf?dl=0 (download the file for better resolution). The quote by Heimann is about 1/5th from the bottom. // IP 78.82.82.235


 * Thank you. I have sent it to my Swedish friend.
 * Please respond to the other issues.
 * Your recent edits rest upon a presupposition that de Weerth's dissertation work actually replicated Plooij's research. RS are quoted in the article stating constraints on the selection of mother-daughter dyads, stating that her selections failed to meet this standard in several ways, and stating why as a consequence her work was not a replication. Your proposed edits must be supported by RS that demonstrate that this assessment of her work is incorrect. Specifically, you must cite RS that state why the identified extrinsic sources of stress in her selected families are irrelevant.
 * You must also support the claim in your proposed edits that the three replications of Plooij's work were "less robust" than de Weerth's. Has a rejoinder to those replications been published?
 * Bn (talk) 03:13, 6 April 2021 (UTC)
 * I have just folded a more complete quote into section D above, together with quotations from Regression periods in human infancy (Heimann 2003). If you consent, I would like to strike through superseded portions of this present exchange with you, to reduce clutter in this workspace toward NPOV.
 * You might consider logging in. Some editors and admins look askance at an anonymous IP address.
 * Bn (talk) 23:17, 6 April 2021 (UTC)

Facts of uncertain status:
 * 1) van Geert's theoretical frame of reference predicts chaotic development. This is obvious in the biographical article about him and in the reference presently given.[Repetition]

Please add to or recategorize these facts from a neutral point of view, and please limit discussion until we are clear what subset calls for work to reach NPOV consensus. Bn (talk) 20:14, 3 March 2021 (UTC)

I have sorted out some confusing references, inserted A-D indices on the four categories of facts for clear reference, and inserted a new reference (D6) to Mende et al. With minor exceptions, deletions are made visible with the strikethrough template. Bn (talk) 21:41, 7 March 2021 (UTC)

Highly biased
This article is highly biased in favor of wonder weeks despite the fact that every child psychologist will tell you they aren’t based in science. 154.27.250.159 (talk) 16:39, 11 February 2022 (UTC)


 * The article is about the book and refers to the science on which it is based, so references to contrary theoretical constructs are necessarily subordinate. This is not bias, it is sticking to the subject.
 * Disagreement in science is not absence of science. The scientific basis of the research underlying this book is in the application of control theory to modeling the functioning of living things (beginning with Norbert Weiner 1948 and developed from the 1950s to present as Perceptual Control Theory). The observational methodology was adapted from ethology (beginning with research with primate mothers and infants, in association with Jane Goodall). These two aspects are amply represented in the "Further Reading" section of the book (pp. 449-452 of the 2019 edition). Bn (talk) 21:21, 14 February 2024 (UTC)

Controversy section is biased
This section does not neutrally outline the controversy but instead presents it in a manner that supports the Wonder Weeks author. Compare his this section us written vs this NYT article covering the controversy: https://www.nytimes.com/2020/04/15/parenting/baby/sleep-regression.html 2603:7080:ED40:6E00:90C8:B353:F7E7:D78B (talk) 16:56, 14 June 2022 (UTC)


 * This unsigned comment seems to propose that the author's point of view should not be represented at all, and that this would be a neutral point of view. Bn (talk) 14:23, 16 February 2024 (UTC)

Neutrality, redux
I'm re-adding an NPOV tag here, because it's clear that while there aren't any ongoing controversies, that seems to be mostly because there's only one engaged editor on this page and people on the 'other side' haven't stuck around long enough to address the controversies.

Personally, I have the following specific concerns:


 * The wording itself reads like an advertisement. In fact, when I first saw the article, I assumed that was what had happened, the article had been written by somebody with a conflict of interest. Some examples here:
 * "Drawing on many years of observation and analysis of infant development, it gives parents practical guidance to help their baby's cognitive development"
 * "This book derives from almost five decades of research"
 * .. and there are many, many more.
 * The article engages in inappropriate synthesis - that is, it draws its own conclusions rather than taking those conclusions from reliable secondary sources. Some examples:
 * "This conclusion, which is consistent with their commitment to the application of mathematical concepts of chaos and complex systems to psychology" appears to be sourced to an article written by the pair that, according to us, does that. The source does not state that those two people are 'committed' to applying said concepts, nor does it explain how the article is 'consistent' with such a commitment. Frankly, this reads as an attempt to disparage the authors rather than a serious point.
 * In synthesizing, the article does not honestly summarize the state of research. For example, "The findings of Plooij and his colleagues have been replicated by three independent research groups." is sourced to four articles, three of which are chapters of the same book, which Plooij is a coauthor of, the remaining study shares an author with one of the other sources. Worth noting that this question of 'independent replication' is actually addressed by the NYT article, so there isn't actually a need for synthesis here - in particular, it's noted that only one of the studies mentioned is actually peer reviewed. There's also no mention anywhere in the article of the concern that all of this research is linked to very small sample sizes.
 * I'm not in the field, so I don't know how normal this is... but that's precisely why we should find a reliable secondary source who can tell us! The reader should not have to guess (and we should not take a position on) whether three studies, only one of which is peer-reviewed, published in the same book, with the main proponent of a theory as a co-author, counts as "replicated by three independent research groups".
 * Another example is "Such difficulties and their effects on the developing child are serious matters for further research, but are not within the scope of this book" in the section about stressors. To some extent you can argue both sides here, but I would personally suggest that you can equally think of this as a limitation of Plooij's research - that is, that it only works if there are no external stressors.
 * There are also a variety of statements that appear to invite synthesis from the reader (in Law & Order I've heard the phrase "more prejudicial than probative"). The article simply names denigrating findings without the benefit of reliable secondary sources to put those findings into context. Particularly egregrious is 'One of these two infants was separated from her mother for ten days because the mother "was not up to it".' This sentence is clearly intended to create a certain impression in the mind of the reader, but it does not actually contextualise the impact on the study.
 * Finally, a small example is "De Weerth's observational data consequently showed the predicted regression periods only for the fourth mother-infant dyad, who were relatively free from extrinsic sources of stress." - the word "consequently" here is doing a lot of heavy lifting, but it's not sourced! There's no evidence presented in the article that one was a consequence of the other, it's just assumed.
 * The article disproportionately depends on sources by the author of the book, when other major secondary sources exist. A bunch of comments above address the 2020 New York Times article. It does seem to be a significant secondary source that should be taken seriously. In this article, it's only addressed as a footnote to "Questioning of the research with mother-infant dyads has received some attention in the press and social media, though sometimes reducing it to a matter of sleep schedules." This comment is almost disparaging about the secondary source
 * A lot of the remaining literature cited all comes from the same book (the link is broken, by the way).
 * You can also see this in the "controversy" section. There are only 1-2 sentences describing de Weert's findings, and then three full paragraphs dedicated to refuting them. There's an unsourced assertion that "No rejoinder has been published to the several 2003 refutations".

There might be more, but it's nearly 5am and my newborn probably needs a feed. But hopefully this provides some concrete areas to work on with respect to making this article faithfully describe the state of research from a neutral point of view. &mdash; Andrew Garrett  &bull; talk 18:52, 25 August 2022 (UTC)


 * Agreed. The article seems to be entirely rewritten by Bn, such that almost nothing of the original article remains and all balance has been erased. This is not a collaborative article but simply a one-man endeavor. I suggest we revert back to the article predating to Bn, re-add in some of their work, and propose that they no longer edit directly because they're clearly unable to work collaboratively after many years of running roughshod over this article. Mvolz (talk)
 * I submit as evidence the following from the "Who Wrote That?" Tool: BN has re-written most of the page. Screenshot of Wonder Weeks page.png Mvolz (talk) 09:38, 25 September 2022 (UTC)


 * I agree. Serious issues of POV editing, editorialising, and ownership here. Fences  &amp;  Windows  21:46, 26 August 2022 (UTC)


 * I've now tried to fix this to make it more neutral. Mvolz (talk) 12:24, 17 December 2023 (UTC)
 * @Werdna, I invite and would very much welcome your participation in editing this article. There is little point in delving into content of a deleted version. To the first of your comments above,
 * "Drawing on many years of observation and analysis of infant development"
 * "it gives parents practical guidance to help their baby's cognitive development"
 * "This book derives from almost five decades of research"
 * These are factual statements that are relevant. You perceive a problem of tone. These facts are represented in today's edit. Do you still see them as advertising?
 * I salute you as the dad of a newborn two years ago next August! I trust that all is well. My daughters are grown, and have greatly appreciated this book with their small children. Bn (talk) 17:46, 19 February 2024 (UTC)


 * : You have, yet again, almost completely re-written the article (this time 87.5%) against consensus. This is a collaborative  encyclopedia. It is not your personal soap box. Of course, you are allowed to make contributions, but your repeated and total re-writes have shown you have failed to learn, and are just repeating the same mistake over and over, which is wasting all of our time. If you do this again, I will pursue a topic ban. Mvolz (talk) 18:54, 11 March 2024 (UTC)