The Phantom Broad Autism Phenotype: When Science Meets Community

What happens when an entire community of experts says the thing you're studying doesn't actually exist?

In this investigative deep-dive, Anita examines the Broad Autism Phenotype (BAP) - a widely accepted scientific concept claiming autism-related traits exist on a continuum in families. But when autistic researchers were finally asked what they thought, their responses should have revolutionized the field.

Join Anita as she unravels the story of twenty autistic researchers, a survey that challenged decades of genetic studies, and Nick Chown's groundbreaking question: Are "autistic traits" real or mythical?

This episode reveals:

• Why do BAP prevalence estimates range wildly from 2.6% to 80%
• How researchers use "autistic traits" without defining the term
• What autistic scholars actually think about this research
• Why do the same behaviors get pathologized in some contexts but not others
• An alternative explanation that could change everything

"Everyone stims, but we only call it that and pathologize it when certain neurodiverse people do it." - Alyssa Hillary, autistic researcher

This isn't just about one research concept - it's about whose voices get heard in science, what happens when communities challenge established narratives, and why we need research WITH autistic people, not just ON them.

The broad autism phenotype might be a phantom, but autistic community wisdom is very real.

Content note: Discussion of genetic research and pathologization of traits.

Transcript

Neurorebelpodcast: 0:03

Have you ever had one of those moments where something that sounds perfectly reasonable suddenly doesn't? I had one recently while reading autism research. I kept encountering this concept called the broad autism phenotype, and what I discovered was a story about 20 autistic researchers, a survey that should have been front-page news, and a question that might change how we think about autism entirely. I'm Anita, and this is Neuro Rebel. Welcome to Neuro Rebel, the podcast that challenges conventional narratives about neurodivergence with research-informed analysis and unapologetic authenticity. I am your host, Anita. I'm autistic, a gifted retired law professor, and a proud resident of Mexico, where I create content that bridges academic rigor with lived experience. If this is your first time here, welcome to our community of Critical Thinkers and rebels. We don't do inspiration porn, we don't oversimplify, and we definitely don't romanticize neurodivergence. Instead, we deep dive into the science, challenge the assumptions, and center the voices that matter most: ours. Before we begin today's investigation, a quick favor. If this podcast adds value to your life, please take 30 seconds to follow or subscribe on your platform of choice. Share it with someone who needs to hear these conversations. Leave a review, and if you're feeling generous, it helps other people find us in the algorithmic wilderness. If you want to support us financially, you can find links to do so in the show notes. Now, let's get rebellious. The concept I stumbled across is called the broad Autism Phenotype, or BAP for short. And on the surface, it made complete sense. The idea is elegantly simple. Autism runs in families, so family members of autistic people might have what researchers call subclinical autistic traits. You know the picture. Maybe a parent who's always been a bit awkward socially has intense interests that border on obsessive or shows some rigid thinking patterns. Not quite enough for an autism diagnosis, but definitely something. Geneticists love this concept because it suggests autism exists on a continuum. That these traits represent what they call genetic liability for the condition. Reasonable, right? I thought so too. The research seemed solid, twin studies showing high heritability, family studies documenting elevated traits in relatives, even brain imaging studies showing neurological differences in family members who display these characteristics. But then I started digging deeper, and what I found was a story about the gap between what science claims to discover and what communities already know to be true. Today we're going detective. We're going to examine a scientific concept that has shaped how we think about autism, genetics, influenced genetic counseling practices, and potentially pathologized normal human variation on a massive scale. And we're going to ask a simple question: what happens when an entire community of experts. That is, autistic researchers say the thing you're studying doesn't actually exist. Let me paint you a more detailed picture of how the broad autism phenotype typically gets presented in research and clinical settings. The story usually goes like this. Leo Kanner, who first described autism in 1943 noticed that parents of autistic children often seemed to share certain characteristics. They were, in his words, strongly preoccupied with abstractions of a scientific, literary, or artistic nature and limited in genuine interest in people. Fast forward 80 years. And this casual observation has evolved into a major research enterprise. Modern. BAP research focuses on three main domains that mirror the autism diagnostic criteria: social communication challenges. Restricted interests and repetitive behaviors and what researchers call, diplomatically, the rigid personality traits. The idea is that family members of autistic individuals show these characteristics at higher rates than the general population, but at subclinical levels. The genetic evidence supporting this concept is genuinely impressive. Twin studies consistently show heritability estimates for autism approaching 90%. Recent polygenic score studies, that is where researchers aggregate the effects of thousands of genetic variants, can predict not only autism diagnosis, but also these subclinical traits in family members. Neuroimaging studies have found structural and functional brain differences in relatives who show BAP characteristics. Now, as someone who spent decades in academia before transitioning to advocacy, I know how seductive this kind of converging evidence can be. When multiple methodological approaches, that is, genetics, brain imaging, behavioral assessment, all point in the same direction, it creates what we call scientific consensus. But here's where my dual identity as both an academic and an autistic person created an interesting tension. The more I read about BAP, the more something felt off. Not wrong. Exactly. But incomplete, like looking at a magic trick where you can see all the moves, but still can't figure out how the rabbit got into the hat. The first red flag was methodological. A systematic review published in 2018 found that prevalence estimates for BAP ranged from 2.6% to 80% across different studies. Let me repeat that. 2.6% to 80%. Now, I don't know about you, but when I see a methodological variation like that, my academic alarm bell starts ringing. That's not a measurement of a stable biological phenomenon. That's methodological chaos. But the more I dug. The more I encountered something, even more troubling. Definitional ambiguity. Despite hundreds of research papers using the term autistic traits, there was remarkably little effort to define what researchers actually meant by this term. Think about it for a moment, if you're going to build an entire research program around measuring autistic traits in the general population. Shouldn't you start by clearly defining what is an autistic trait or what makes a trait autistic? You would think so, but paper after paper simply assumed readers would understand the concept without an explanation, without a definition. This isn't just academic nitpicking; if we can't clearly define what we are measuring, how can we be confident we're measuring anything meaningful at all? It's like trying to study tallness without defining what height threshold makes someone tall. And that's when I remembered something: a mentor once told me that when the experts disagree, find out what the people living the experience have to say, which led me to ask a question that frankly should have been asked decades ago. What do autistic researchers think about this concept? Turns out someone had asked that question, that very same question, an autistic independent scholar named Nick Chown published what should have been a paradigm- shifting paper in 2019. The title alone should have made every BAP researcher pause. The title? Are the Autistic Traits and Broader Autism Phenotype Concepts Real or Mythical? Now, Nick Chown isn't some random blogger with an opinion. He's a scholar with deep expertise in autism research methodology, and he approached this question with the kind of systematic rigor that makes academics weep with joy. What made his analysis particularly powerful was his insider knowledge. He is autistic himself, so he understood both the research and the lived experience it claimed to represent. Chown did something that was simultaneously brilliant and simple. He looked at how researchers actually used the term autistic traits and analyzed whether it had any coherent meaning. What Chown discovered was startling. Despite being used in hundreds of research papers, the term autistic traits was almost never explicitly defined. Researchers were engaging in what he called a language of gain. Everyone assumed everyone else knew what they meant, but nobody actually spelled it out. This isn't just semantic hair-splitting; language shapes thought, and unclear language leads to unclear thinking. When researchers use terms like autistic traits, without definition, they're making implicit assumptions about the nature of autism that may not be valid. But Chown didn't stop at linguistic analysis. He did something that frankly should be standard practice in autism research, but rarely happens. He asked autistic researchers what they thought about the concept their non-autistic colleagues were studying. Chown surveyed 20 autistic autism researchers, people with both lived experience and academic expertise. These weren't random community members. These were scholars with advanced degrees, published research, and a deep understanding of autism literature. The question he asked them was deceptively simple. Do autistic traits exist as a discrete and measurable entity? The responses he got should have sent shockwaves through the autism research community. But before I share what they said, let me ask you something that might help you understand why their answers were so significant. Think about behaviors you might consider as autistic traits. I don't know, maybe stimming repetitive movements or sounds, difficulty with eye contact or intense focused interests, perhaps preference for routine and predictability, or a need for quiet, low stimulation environments. Got those in mind? Okay. Now here's the question that changed everything for me. Are any of those behaviors actually unique to autistic people? Take stimming for example, do only autistic people fidget, tap their feet, play with their hair, or engage in repetitive movements? Of course not. Neurotypical people stim constantly. They just don't call it stimming and nobody pathologizes it when they do it. What about intense interests? Are autistic people the only ones who become deeply absorbed in specific topics, collect detailed information, or spend hours engaged with their passions? Obviously not. When neurotypical people do this, we call them enthusiasts or experts or passionate, but when autistic people do it, it becomes a restricted interest that needs intervention. Do you see the pattern emerging? Another autism researcher, Luke Bearden crystallized this insight perfectly. He observed that there is no such thing as autistic behavior. There is no single behavior or set of behaviors displayed by autistic people that can't be seen in non-autistic people. Think about that for a moment. Think about the profound implication of that statement. If there are no behaviors that are unique to autism, then what exactly are researchers measuring when they assess autistic traits in family members? What makes a trait autistic versus just human? Now I can share with you what those 20 autistic researchers told Chown and why their responses should have revolutionized how we think about BAP research. Alyssa Hillary from the University of Rhode Island provided perhaps the clearest articulation. She said, using your definition, I'd say there is no such thing as autistic traits or autism traits. They just don't exist. I don't think there are any universal traits of the type you described that you can ascribe to autistic people. There is no such thing as an action that's unique to autism. Everyone stims, but we only call it that and pathologize it when certain neurodiverse people do it. Let that sink in for a moment. A researcher with both lived experience and academic expertise is saying that the fundamental concept underlying decades of BAP research, that idea of measurable autistic traits, doesn't actually exist. But it gets more interesting. Other survey respondents noted the cultural and social construction aspects of trait identification. Several pointed out that the same behaviors are interpreted differently depending on who exhibits them. When displayed by someone already labeled as autistic or from an autistic family, behaviors become autistic traits, but when displayed by others, they're just personality quirks or individual differences. Yes. Do you see what's happening here? We're not measuring biological phenomena. We are measuring social labeling processes. The broader autism phenotype might actually be documenting how we selectively pathologize normal human variation when it occurs in certain contexts. This has profound implications for all that impressive genetic and neuroimaging research I mentioned earlier. If the traits being measured aren't actually distinctly autistic, but rather normal human variations that get labeled differently in different contexts, then what exactly have those studies been documenting? But Chown proposed something even more revolutionary. What if the evidence typically cited to support BAP isn't actually evidence for subclinical traits at all? What if it's evidence that autism is more common than we currently recognize? Think about that. What if many individuals labeled as having subclinical autistic traits are actually autistic, but undiagnosed? What if BAP research has been documenting the presence of additional autistic people and families already affected by autism, rather than documenting genetic liability for subclinical traits. This alternative explanation would account for so much. The familial clustering of traits, the high heritability estimates, the neuroimaging differences, even the wildly variable prevalence estimates. Different studies might be capturing different proportions of undiagnosed autistic individuals depending on their methodology and population. This explanation becomes even more compelling when you consider the historical context of autism diagnosis. We know that autism has been systematically underdiagnosed in women and people of color and individuals without intellectual disabilities, and in people who developed effective masking strategies. Many autistic adults describe recognizing their own autism only after their children were diagnosed. Rather than representing subclinical traits, these patterns might simply reflect the intergenerational transmission of autism in families where it has been historically overlooked. The possibility that BAP traits represent undiagnosed autism rather than some clinical phenotypes isn't just academically interesting. It's personally and politically significant. It shifts the narrative from genetic liability for pathology to unrecognized neurodiversity. So what does this mean for science? Where does this investigation leave us? I think it reveals something profound about how scientific knowledge gets constructed and whose voices get heard in that process. The BAP story isn't just about one research concept gone awry. It's a case study in what happens when research proceeds without meaningful input from the communities being studied. It's about the difference between studying people and studying with people. For decades, researchers have been measuring, categorizing and theorizing about traits in autistic families without centering the perspective of autistic people themselves. When autistic researchers finally got asked what they thought about the fundamental concept underlying this research, their response was essentially, this doesn't exist the way you think it does. The methodological implications are staggering. If the critique is correct, then hundreds of studies, millions of dollars in research funding. An entire theoretical frameworks may be based on a conceptual error, not fraud. Not bad science in the traditional sense, but a fundamental misunderstanding of what was being measured. This raises uncomfortable questions about research quality control. How did a concept with such fundamental definitional problems become so widely accepted? Why wasn't community input sought earlier? What other research concepts might benefit from similar scrutiny? But beyond the academic implications? This has real-world consequences for autistic people and their families. BAP research has influenced genetic counseling practices, shaped how families understand themselves, and contributed to conversations about autism prevention. If the neurodiversity critique is correct, if these so-called subclinical traits actually represent normal human variation or undiagnosed autism, then framing them as genetic liability becomes not just scientifically questionable, but ethically problematic. The language of genetic liability implies that these characteristics are undesirable. That they represent risks to be managed rather than differences to be understood and accommodated. But here's what gives me hope and why I wanted to share this investigation with you. The same research that has been used to support BAP actually points towards something much more interesting and affirming. What if autistic traits aren't deficits or liabilities at all? But simply variations in human neurological functioning. What if the genetic findings don't document pathology, but rather the heritability of neurodivergent ways of being? What if instead of trying to prevent or predict autism, we focused on understanding and supporting the autistic people who are already here. Imagine autism research that starts with autistic experiences instead of trying to explain them away, or research that asks, How can we create more accessible environments instead of How can we make autistic people more normal? Or research that views autistic traits as potentially valuable contributions to human diversity rather than problems to be solved. If you take one thing from this investigation, let it be this. The next time you encounter autism research or really any research about marginalized communities, ask yourself some questions. Who was included in designing this study? Who was included in interpreting the results, whose voices were centered and whose voices were marginalized? Demand that research include the communities it studies as partners, not just subjects. Support researchers who are members of the communities they study. Question, research that pathologizes difference without considering alternative explanations. And for my autistic listeners specifically, trust your instincts about research that doesn't ring true to your experience. Your lived experience matters. Your perspectives are valuable. The fact that you've been excluded from much of the research about you doesn't make that research more objective. It makes it incomplete. I started this investigation thinking I was examining a scientific concept. I thought I was gonna learn something new. I ended up discovering something much more important. I did discover something new that the power of community knowledge and the courage of researchers willing to question established narratives can make a world of difference. The broad autism phenotype might indeed be a phantom, but the autistic community's wisdom is very real and it's time the research world started listening. You've been listening to Neuro Rebel. And I'm your host, Anita. If this episode challenged your thinking, validated your experiences, or simply gave you something to ponder, please share it with someone who needs to hear it. Our next episode will explore how these same concepts are being exported to Latin American contexts often inappropriately. We'll examine scientific, colonialism, cultural adaptation of research, and why global neurodiversity advocacy must be culturally responsive. You can find show notes, transcripts, and additional resources@neurorebelpodcast.com. Follow us on social media. We're@neurorebelpodcast for updates and continued conversation. And if this work adds value to your life, consider supporting it financially through the links in our show notes. Remember, we don't need to be fixed or cured or prevented. We need to be understood, supported, and valued for who we are until the next time, thank you so much for listening. Keep questioning, keep challenging, and keep being beautifully unapologetically, neurodivergent. This has been neuro rebel.