Risky business: How assumptions about evidence can exclude autistic voices

Abstract

Gestalt Language Development has been proposed as a theoretical foundation for neurodiversity-affirming intervention, yet its adoption remains controversial. Critics cite limited high-quality research as justification for rejecting its use, raising valid concerns about its scientific backing. However, such rejection rests on two assumptions that may lead to risky clinical decisions: (1) that research evidence should be the sole or primary driver of evidence-based practice and (2) that research-backed interventions are inherently neurodiversity-affirming. Using Gestalt Language Development as an example, this letter critiques these assumptions and illustrates how over-reliance on research alone—without integrating clinical expertise and autistic perspectives—can delay meaningful, inclusive care. I argue that centering autistic voices is essential to both neurodiversity-affirming practice and evidence-based decision-making. A more balanced model of evidence-based practice is needed—one that evaluates emerging interventions not only by their research base but also by their alignment with autistic values and their impact in clinical practice.

Lay Abstract

Many autistic individuals and clinicians find Gestalt Language Development to be a helpful approach for supporting autistic communication. However, some researchers argue that Gestalt Language Development should not be widely used until stronger research evidence is available. This argument introduces two risks. First, it assumes that research is the only kind of evidence that matters—overlooking the value of autistic lived experience and clinical expertise in making good intervention decisions. Second, it assumes that research-based interventions are automatically neurodiversity-affirming, even when they are developed without input from autistic people. This letter argues that excluding autistic voices from intervention decisions is risky. A more balanced approach to evidence—one that includes autistic perspectives, clinical expertise, and research—leads to inclusive, more responsive, and more effective support. While research on Gestalt Language Development is still growing, real-world experiences from autistic people and families offer valuable insight into what works and why it matters.

Ongoing debates about Gestalt Language Development (GLD) focus on its theoretical role as a foundation for neurodiversity-affirming interventions (Haydock et al., 2024) and its rejection due to the current lack of high-quality research evidence (Bryant et al., 2024; Venker & Lorang, 2024). However, arguments against its adoption rest on two implicit assumptions that may lead to risky clinical decisions: (a) evidence-based decisions rely solely—or primarily—on research evidence and (b) interventions supported by research are inherently neurodiversity-affirming. In this letter, I critique these assumptions and advocate for a more balanced interpretation of evidence-based practice (EBP)—one that centers autistic voices and integrates multiple, complementary sources of evidence when evaluating interventions that impact autistic individuals.

Assumption 1: research evidence as the only and best source

It is well established that EBP requires the integration of three core sources of evidence: research findings, clinical expertise, and evidence of patient preferences. However, research evidence is often misunderstood as the sole—or most authoritative—determinant of intervention decisions and is frequently positioned as more valuable than clinical expertise (Fissel Brannick et al., 2022) or patient input (Khamis-Dakwar & Randazzo, 2021). Critiques of GLD emphasize the limited availability of high-quality research evidence (Bryant et al., 2024), concluding that its adoption is premature (Venker & Lorang, 2024). These critiques highlight important research gaps, particularly in commercialized, packaged interventions such as Natural Language Acquisition. However, they also rely almost solely on evaluations of quantitative research, which contradicts the core goal of EBP: to reduce bias in clinical decision-making by integrating multiple, complementary forms of evidence. Overemphasizing research findings—without balancing them against evidence from patient perspectives and clinical practice—can lead to the risky clinical decisions that EBP was designed to prevent.

One of these risky decisions is to implement an intervention with strong research backing but little to no autistic input. For example, punishment-based techniques (e.g. response interruption/blocking) that are designed to reduce echolalia are well supported by research (Mantzoros et al., 2022). However, these approaches assume that echolalia is non-communicative—an assumption that contradicts autistic lived experiences (Haydock et al., 2024). Similarly, social skills trainings (SSTs) are widely regarded as research-based yet frequently treat autistic behaviors—such as avoiding eye contact—as deficits to be corrected rather than social differences to be understood (i.e. the Double Empathy Problem; Milton et al., 2022). While autistic and neurodivergent individuals often experience persistent loneliness and express a desire for social connection, SSTs tend to teach “right” and “wrong” ways to be social without incorporating autistic goals or values (Ke et al., 2018; but see Harker et al., 2024). The long-standing use of interventions aimed at reducing echolalia or correcting autistic socialization illustrates the danger of privileging research evidence without integrating evidence of patient preferences.

A second risky decision is to reject emerging intervention approaches that are grounded in clinical expertise and autistic perspectives because they lack high-quality research. This reasoning underlies critiques of interventions informed by GLD, leading to conclusions that any method associated with this framework is ineffective—or even harmful—until proven otherwise (Smith & Pell, 2003). Such conclusions delay the adoption of potentially meaningful, neurodiversity-affirming practices. These delays are not trivial: research takes an average of 17 or more years to reach the populations it is intended to benefit (Butler, 2008). Because rigorous research takes time, GLD-informed approaches naturally emerge first as theory-informed practices—grounded in autistic cultural values and clinical evidence. Rejecting these on the basis of research alone reflects a narrow interpretation of EBP, one that fails to consider why these approaches are gaining traction. Ironically, it is the lack of autistic-informed, neurodiversity-affirming intervention options that is driving clinicians and families to use GLD-informed practices—because they reflect, rather than ignore, autistic values and lived experience.

Frameworks exist for generating and integrating clinical evidence (Fissel Brannick et al., 2022) and evidence of patient preferences (Khamis-Dakwar & Randazzo, 2021), both of which can help balance the limited research base for GLD-informed interventions. These sources are integral to EBP and can be used to inform and adapt treatment decisions as more research emerges. Autistic individuals would be better served if the scientific community approached current debates about GLD not as a barrier to be overcome, but as a bridge toward collaborative refinement, inclusion, and participatory research.

Assumption 2: research-based interventions are inherently neurodiversity-affirming

Centering autistic values and preferences throughout the intervention process is both a foundational component of EBP and a core tenet of neurodiversity-affirming care. However, the strength of research evidence and the degree to which an intervention aligns with neurodiversity-affirming principles are distinct considerations. Research is typically evaluated based on methodological rigor and statistical significance—yet these criteria alone do not guarantee alignment with autistic priorities. In fact, assuming that any research-backed intervention is inherently neurodiversity-affirming can itself be risky, especially when autistic voices have been excluded from its design or evaluation. Neurodiversity-affirming principles emerged from the autistic self-advocacy and disability rights movements. Its core tenet, nothing about us without us, requires that autistic individuals’ values, insights, and lived experiences be centered in all decisions that affect their lives (Kapp, 2020).

To date, published critiques of GLD have rarely integrated autistic perspectives as central to the debate. In contrast, research that meaningfully includes autistic voices reaches different conclusions—that GLD-informed practices are affirming of autistic and neurodivergent ways of communicating (Haydock et al., 2024). I contend that it is the centering of autistic values itself that is neurodiversity-affirming; a designation that is separate but complementary to research evidence. As conversations about GLD and similar approaches continue, we must evaluate the interventions we promote—and the evidence we rely on—by asking: To what extent were autistic preferences meaningfully incorporated from the beginning? Framing this question as a minimum standard for neurodiversity-affirming care grows the field toward a broader and more balanced interpretation of EBP: one that organizes research and clinical decision-making around autistic values.

Conclusions and future directions

Research evidence, clinical expertise, and patient perspectives represent distinct but complementary sources of evidence. Each carries the potential for bias when used in isolation—but when balanced, they provide a more inclusive, equitable, and effective foundation for evidence-based decision-making (Fissel Brannick et al., 2022). Examples of how to center autistic voices in intervention planning are increasingly visible in research and clinical practice (e.g. Harker et al., 2024; Zervogianni et al., 2020). These models offer a promising precedent for centering autistic perspectives more consistently in scientific discourse. As debates about GLD-informed interventions continue, autistic individuals must be recognized as experts on their own experiences. Excluding their voices from these conversations is a risky practice that undermines the inclusivity, equity, and effectiveness of evidence-based decision-making. Centering autistic voices will not only improve intervention outcomes—it will better align our practices with the goals autistic individuals have for themselves.