[TL;DR: GLP and the associated theory of NLA have become very popular but continue to lack adequate theoretical bases or adequate testing. Caution and healthy scepticism are advised.]
I’ve begun to see claims about children being Gestalt Language Processors (GLPs) turning up very regularly in various education, literacy, and autism groups. If a child is a GLP, this is meant to have implications for the best intervention to use with them, so this is important: Understanding the theory and practices related to GLP should make someone a better educator and interventionist. That is, if GLP is a real thing, and if the practices built around GLP being real were proven effective. Therein lie the problems though; problems I am going to explain here. The problems are complex and many, so I’m going to try to break them down to be more accessible.
My hope is that by the end of this you will feel better informed about the GLP controversy, and may even feel empowered to pushback against the GLP movement as it currently stands, because it absolutely deserves that pushback. You would not be alone in that pushback either; some powerful and highly respected international experts, like Caroline Bowen, are right there alongside you.
Let’s start with the proposed explanation of what a GLP is:
If a child is a GLP then their speech has included echolalia. Echolalia is the repetition of a sentence or phrase heard from someone else (either recently heard or heard from a very long time ago, the time frame is not the key). The "echo" may not seem meaningful in the context in which the child later uses it. Echolalia occurs in children who are going through standard speech development, and those with delayed or abnormal speech development, but is particularly noticeable in autistic children who may use echolalia for longer or more frequently than typically developing children. Therefore, the suggestion is that some typical children and the majority of autistic children are GLPs.
The “gestalt” part of the term GLP is particularly focused on the notion that these children approach language from the whole to the part (as opposed to the part to the whole). They start with chunks of language and then break it down over time into its parts, rather than starting with parts (such as words) and building up to sentences. The latter would be called Analytic Language Processors (ALPs). The suggestion is children are either GLPs or ALPs, and furthermore that whether they are one or the other should change the way we approach language intervention.
With me so far? We have GLPs (particularly in the autistic population), and ALPs. And whether a child is one or the other is particularly dependent on their use of “echoes” – engaging in echolalia. Let’s add one more vital 3-letter initialism to the mix: NLA.
NLA stands for Natural Language Acquisition. It is a theory directly linked to the existence of GLPs, and claims GLPs move through six stages, and furthermore that we can use these stages to choose the most effective approach to advance their language acquisition.
Right, all sound good so far? So, where’s the problem? Let’s take these issues one at a time. There are definitely crossovers between the points I’m sharing below (for example, quite a few are about the evidence base), but I think it helps to try to split them into different sections to help identify separate issues contained within the same general area of complaint:
(1) The evidence base for GLPs and NLA is extraordinarily weak. It is largely composed of case studies and anecdotes, and some key founding case studies aren’t even of students who struggled with language acquisition, yet that evidence is used to found theories and practices aimed at struggling language learners. Evidence like case studies can have an important place in research but they lack predictive power, and therefore the ideas of GLP and NLA require further testing and empirical research before they should be used with vulnerable populations in particular:
“Anecdotes are not only vulnerable to confirmation bias and survivor bias (those for whom the intervention did not produce results tend to not be solicited) but because they are based on individual experience, they provide no probabilistic information on the likelihood that something will occur (in this case a therapeutic effect) which requires systematic observations with larger numbers of people” (Hutchins et al., 2024).
(2) There are alternative, well-established, evidence-based practices that have been shown to have predictive power and have strong histories of being effective, including with autistic children: “[T]here is a substantial body of literature outlining evidence-based interventions designed to enhance communication in autistic children and adults, which include the use of (a) AAC systems (e.g., visual supports, speech generating devices, graphic symbols, visual scenes displays, mobile technologies such as phones and iPads with AAC apps) (e.g., 10, 11); (b) play-based interventions focused on vocalization, initiation and joint attention (e.g., 12, 13); and (c) strategies implemented by communication partners, including interpreting meaning in the person’s spoken communication, vocalizations, or non-verbal communication” (Bryant et al., 2024).
To substitute out these evidence-based practices, with non -evidence-based practices based on GLP/NLA that run counter to them, can be considered unethical and unprofessional. At the very least, families should be informed of the lack of evidence for GLP-based approaches: “Clinicians working with children with neurodevelopmental communication disability have an ethical responsibility to ensure parents are informed of the apparent lack of research into these practices” (Bryant et al, 2024).
There are limited resources available to families and professionals, particularly in terms of time and money, and delaying the use of effective practices with vulnerable students can have long-term consequences for their mental well-being and educational outcomes, so those limited resources should not be put towards non-evidence-based practices:
“Providing interventions that are not known to be effective, or known to be ineffective, without appropriately determining any significant benefit, is potentially harmful due to: financial, time, and opportunity costs to the client/family; usage of time and expenditure of funds for training of therapists; wasteful use of scarce therapy resources; and lost opportunity through the passage of time in the developmental trajectory of the child” (Bryant et al., 2024).
(3) Tied into the evidence issues highlighted above: Where good outcomes are claimed to be caused by using a GLP/NLA approach, there have not been controls for (a) the use of other (evidence-based) approaches at the same time as the GLP/NLA approach, and (b) the natural progression that can happen as children age (a progression that is typically delayed with autistic children). This is why we need more tests, and large-scale independent testing, to make sure we’re not just measuring those other well-established factors in language progression (see Bowen’s discussion in the UTS podcast, 2024).
“The systematic search and review of records identified no empirical research evaluating the effectiveness of approaches related to GLP/NLA” (Bryant et al., 2024).
(4) There are positive aspects in GLA/NLA approaches, such as responsiveness and recognising the role of echolalia, but those positives did not derive from GLA/NLA, they are not exclusive to GLA/NLA, and they do not necessitate acceptance of GLP/NLA. In fact, the positives within GLP/NLA theory and practices came from other evidence-based practices and can be incorporated into evidence-based practices. There is no unbreakable bond between neuro-affirming, echolalia-accepting, responsive practices, and using a GLP/NLA approach. (Indeed, it has been attacked for trying to equate “neuro-affirming” with a non-evidence-based practice, as wasting the time and money of neurodivergent people is not in their best interests.)
“NLA advocates have raised awareness of the communicative value of echolalia while advancing the use of many time-honored, evidence-based speech-language practices (e.g. honoring preferred modes of communication, following the child's lead, maintaining a high degree of responsivity, engaging in motivating contexts). These practices are neither novel nor developed exclusively for autistic children (and certainly not unique to NLA; e.g. Hanen)” (Hutchins et al., 2024).
(5) There is the suggestion that GLP/NLA theory and practices have misunderstood echolalia, or at the very least have significantly overstepped what we know at this point about echolalia. GLA/NLA assumes that echolalia is a resource for language progression – that we must utilise it as a specific stage, with consequences for how to approach a child in that stage, to help GLPs. However, evidence at this time supports the idea that the presence of echolalia predicts language progression, rather than being a source we must draw upon to achieve language progression; “empirical support for delayed echolalia as source material for autistic language learning is woefully lacking” (Hutchins et al., 2024).
Echolalia is better understood as a tool that is used by the child while more sophisticated language is still developing, rather than a necessary step on the journey. As that more sophisticated language develops, the use of echolalia decreases because its usefulness decreases (this in no way means we should try to eradicate echolalia – it is neither standing in the way of language development, nor necessary for language development).
Considering how much of GLP/NLA theory and practices are built around a specific understanding of echolalia, this should raise serious questions about their very foundations. “[U]se of NLA stage supports demands acceptance not only of the raw material view of delayed echolalia but an extreme version of that hypothesis: one where delayed echoes are the ‘foundation of gestalt language development’ (Blanc, 2024, p. 3), linguistic analysis of gestalts is ‘all or nothing’ (2012, p. 14), and GLPs ‘need to go through the steps’ (2012, p. 9) to advance their language” (Hutchins et al., 2024).
(6) There is a second issue with how GLP theory presents echolalia and the idea that it’s presence is linked to whole-to-part thinking, when we recognise that echolalia can actually occur at the single-word level too: “it is uncontroversial that delayed echolalia routinely takes the form of phrases as well as single words. If delayed echolalia reflects an extreme form of gestalt processing and problems extracting units at the word level, why do so many minimally-speaking autistic children do so with frequency?” (Hutchins et al., 2024).
(7) GLP theory misrepresents what we know about autistic strengths: Plenty of research has found that part-to-whole (analytic) approaches are a strength of autistic people, to the extent that it can become a specific challenge for autistic people to get beyond seeing the parts to seeing the whole things that they compose. Autistic people are particularly known for their detail-oriented processing. Yet the gestalt theory rests on the idea that autistic minds operate with particular strength in whole-to-part thinking; “it neglects decades of research demonstrating strength in detail-oriented processing” (Hutchins et al., 2024).
This mismatch should not only raise questions about a gestalt approach to helping autistic people, but also raise concerns about mispresenting the strengths of autistic people more generally – squeezing them into a model that actually works against their strengths.
( 8 ) GLP/NLA ignores the actual heterogeneity of autism.It draws on unsupported statistics of how widespread the incidence of GLP is, to categorise autistic people as being dominantly GLPs and otherwise pigeon-hole them as ALPs. The binary division of GLPs versus ALP, and declaring autistic people to be dominantly GLPs, ignores the true diversity of autistic people and the need to build any intervention in response to that diversity; “hasty generalization to almost all people with autism neglects the heterogeneity that defines the condition and invites misunderstanding and stereotyping of autistic people” (Hutchins et al., 2024).
(9) The simple division at all of people into GLP and ALP ignores the fact that people typically engage in both types of strategies; it is too simplistic to divide people into one or the other camp. “If it is unhelpful to characterize any persons or groups as natural born ‘gestalt’ or ‘analytic’ processors, this has clear consequences for NLA which hangs on the assertion that (most) autistic people are GLPs” (Hutchins et al., 2024).
(10) That ties into the foundational problems with the label of GLP in itself. The way GLP is defined is circular: someone who is GLP uses echolalia, and a person who uses echolalia is a GLP. You can largely replace “GLP” with “uses echolalia” in the literature: “In NLA, a GLP is described as someone who communicates primarily through gestalts (Blanc, 2012) meaning delayed echolalia such that the terms are used interchangeably” (Hutchins et al., 2024). Claiming someone is a GLP isn’t an enlightening category nor a clearly defined construct: “The term ‘gestalt language processor’ is definitionally and conceptually troubled, the assertion that autistic people are GLPs is misleading and unhelpful, and evidence is lacking that GLP represents a legitimate clinical entity” (Hutchins et al., 2024).
(11) The six NLA stages are problematic: Evidence better supports a gradual progression in language acquisition, rather than a stepped/stage-like progression that could be used to divine a matching intervention at each stage. “Blanc's stages might be better classified as pseudostages where it is understood that continuous phenomena are being carved into arbitrary categories” (Hutchins et al., 2024).
This is true for autistic as well as typically developing children. “Generally speaking, research suggests that the morphosyntactic development of autistic and NT children ‘is more similar than dissimilar’ (Kim et al., 2014, p. 345), commensurate with developmental age across the spectrum (Boucher, 2012; Boucher & Anns, 2018, Tager-Flusberg, 1981a, 1981b), and gradual and continuous as opposed to abrupt and step-like” (Hutchins et al., 2024).
Even the recommendations for figuring out which stage a child is at in the NLA progression show that children can sit across three stages at the same time (for instance), undermining the staged theory and different interventions to match each stage is actually helpful. “Although placing an individual into two contiguous stages simultaneously (presumably because a person is on the cusp of change) does not constitute a crisis for a legitimate stage theory, routine assignment of individuals to multiple stages simultaneously is problematic” (Hutchins et al, 2024).
“The theoretical basis of NLA lacks empirical support. NLA stages are implausible” (Hutchins, 2024). “[E]vidence in support of NLA is, to our knowledge, entirely anecdotal” (Hutchins et al., 2024).
(12) The advice for the stages of NLA at times run directly counter to strongly established best practice for advancing children’s language, including a stage where grammar is discouraged and a stage where verbs must be avoided: “recommendations to avoid single words (stage 1), use lots of contractions that obscure the boundary between subject and predicate (stage 2), and model isolated words without regard to grammar while also avoiding verbs (stage 3), do not square with existing research examining the properties of linguistic input that predict and support language development in NT and autistic children (e.g. Butler et al., 2023; Clark-Whitney et al., 2022; Hadley et al., 2018; Naigles et al., 2011). In fact, it is not obvious how NLA stage-specific recommendations would follow from even the raw material view of delayed echolalia on which NLA is founded” (Hutchins et al., 2024).
(13) The theoretical base is generally weak. Blanc (the lead person in the modern NLA/GLP movement) draws on untested suggestions from other researchers and presents them as if they are proven foundations on which to build an entire approach, and overstates the evidence base more generally. For example, “Blanc et al. (2023) claimed that NLA stages were ‘detailed and quantified’ by Blanc (2012) who ‘analyzed 15 years of clinical data collected from the language samples of dozens of autistic and neurotypical individuals who used gestalt style of language development’ (p. 3); however, it should be noted that this work was written and published without peer review and comprises only a handful of informal case descriptions” (Hutchins et al., 2024).
This is in no way an exhaustive list of the concerns raised about GLP and the associated NLA theory and practices. Other concerns include: misunderstanding and counter evidential views about the relevance of episodic memory (see Hutchins et al., 2024); untestable claims because the terms used by GLP and NLA they excessively vague; and that linguistics and developmental psychology emphasise the role of smaller language units (like morphemes and syntax) in learning, as just two of a number of related research areas where GLP/NLA run counter to established (and tested) theories.
Is it possible that there are GLPs, who move through NLA stages, which necessitate different interventions, as presented in the GLP/NLA approach? It appears unlikely considering how much evidence goes against it and the current lack of evidence for it, but let’s say it’s possible anyway. Being possible isn’t enough. We’re talking about highly vulnerable children here.
Once GLP/NLA has undergone adequate, independent testing, with replicated results, it can sit alongside the other options and tools in the toolbox. Once there are clear tests that help identify which type of child would benefit from a GLP/NLA approach versus which would benefit from the other many well-established approaches already out there (as evidenced by comparative and replicated studies), we have a way to identify appropriate candidates. We’re not there yet.
When I started out writing this piece, I had intended to be more neutral; to generally share the issues with GLP/NLA and let people decide for themselves without my opinion clouding matters. However, I realised I couldn’t hold that stance in good conscience, and I recognise this will make me unpopular with some readers who think it’s important to stay open to new theories, so I’ll state my stance as clearly as I can:
GLP/NLA is aimed at very vulnerable children (children like mine who are both autistic, and one of whom engaged in echolalia as the primary mode of verbal communication for an extended period). When we are dealing with very vulnerable children and their equally vulnerable families, it is unethical to encourage them to spend their limited resources (and expend their hope and effort) on untested practices that run counter to tested and effective practices. It is equally a waste of professionals’ time and money to encourage them to pay for books and courses built on such theories. It is the responsibility of those presenting new theories intended for use with such vulnerable populations, to define them clearly and test them adequately before encouraging families and professionals to embrace them by adopting practices that run counter to current best practice guidelines.
None of this means GLP/NLA has been proven wrong; it hasn’t been proven at all. Until it is, families and professionals should maintain a healthy scepticism. Anyone engaging in GLP/NLA based practices should, at the very minimum, be aware of the many concerns about it. I hope this write-up has helped in that regard.
(This post was originally shared in the Effective Education Practices NZ Facebook group, on 25 March 2025: https://www.facebook.com/groups/effectiveeducationnz/posts/999752978290030/ )
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“Natural language acquisition and gestalt language processing: A critical analysis of their application to autism and speech language therapy” (Hutchins et al., 2024) https://pmc.ncbi.nlm.nih.gov/articles/PMC11113044/
“Gestalt Language Processing (GLP) with guest Dr. Tiffany Hutchins” (Super Special Kids podcast episode; 14 February 2025)
“Systematic Review of Interventions Based on Gestalt Language Processing and Natural Language Acquisition (GLP/NLA): Clinical Implications of Absence of Evidence and Cautions for Clinicians and Parents” (Bryant et al., 2024) https://link.springer.com/article/10.1007/s40474-024-00312-z
“Mind the evidence gap : Caution over Gestalt Language Processing / Natural Language Acquisition” (UTS Speech Pathology Podcast, hosted by Hemsley, featuring Bryant & Bowen, 2024) https://omny.fm/shows/whats-got-us-talking-the-uts-speech-pathology-pod/mind-the-evidence-gap-caution-over-gestalt-language
Thank you for writing this. I came to your post via web search, feeling curious but expecting to disagree with you, and I left it realizing that I have a lot of the same questions and concerns; I’d just been assuming that if I found better information, they’d be addressed. My family’s experience makes me think that there’s something interesting in the concept of gestalt communication, but it sounds like NLP might be too simple and binary a framework to get at it. ...Feeling tempted to talk your ears off here, except I realize you probably like your ears just fine right where they are.
Thank you. A parent of a new student of mine mentioned she was a "gestalt language processor" and exhibits echolalia. I knew about echolalia but nothing about the GLP term. I really appreciate this explanation and cautions.