Skip to main content

The Case for Early Dyslexia Screening

Associate Professor Nadine Gaab on how earlier intervention can be the ultimate game-changer when it comes to identifying children with dyslexia and other learning differences
Mother reading with baby

Associate Professor Nadine Gaab wants to see the whole system surrounding children and reading development change — starting in utero. Earlier intervention can be the ultimate game-changer when it comes to identifying children with dyslexia or other learning differences. 

“When it comes to learning differences such as dyslexia, we are largely focused on a reactive deficit-driven wait to fail model instead of the development of preventative approaches,” she says. Gaab is a neuroscientist who researches the development of typical and atypical language and literacy skills in the pediatric brain, and pre-markers of learning disabilities. 

"What we could show is that some of these brain alterations are already there in infancy, and toddlerhood, and preschool. So what we can conclude from this is that some children step into their first day of kindergarten with a less optimal brain for learning to read. So you want to find them right then, right? And that has tremendous implications for policy," she says. "You don't want to wait and let them fail if you already can determine who will struggle most likely and who will not."

While there have been some efforts to mandate universal dyslexia screening, it is only one small part of what needs to be done to take steps toward addressing the needs of children, something that Gaab envisions an entire community — beyond just the school walls — being a part of, from pediatricians to bus drivers to librarians.

In this episode of the EdCast, Gaab discusses what we know and don’t know about dyslexia and literacy development, and why the need for intervention — as early as preschool — could be the most impactful thing that happens. 



JILL ANDERSON: I'm Jill Anderson. This is the Harvard EdCast. 

Nadine Gaab knows early dyslexia screening and intervention could change outcomes for millions of children. She's a Harvard neuroscientist whose research focuses on language-based learning disabilities and typical and atypical reading development. An estimated 5% to 10% of Americans have dyslexia, but screening and diagnosis can be complicated and take time.

Many states have begun mandating universal dyslexia screening at an early grade, but it's only a small piece of what has to be done to move toward what she calls a prevention model. I wanted to know the potential impact of early screening and what's keeping it from happening. First, I asked Nadine to tell me what is dyslexia.

Nadine Gaab

NADINE GAAB: This is actually a very complicated question. And I think if you would ask 50 people to define, it you would maybe get 50 different responses. So the field itself is not really sure how to define it. The way we define it is it's a specific learning disability with a neurobiological origin. So there is a brain correlate to it. And it's usually characterized by difficulties with accurate and/or fluent word reading.

And we want to put the emphasis here on word reading because it's the mechanics of learning to read that usually is the core symptom of developmental dyslexia. So we have poor decoding abilities. You could have poor spelling abilities. And so it's that deciphering of single words, the decoding of single words, that's the core symptom of dyslexia.

Subsequently, it can lead to problems with reading fluently and comprehending what you read. But I think it's really important that we define it at the word level in these children.

JILL ANDERSON: Is that partly why it is so hard for children to be identified as dyslexic?

NADINE GAAB: I think the reason why it's so hard is more a systems level problem than it is the definition of what it is.


NADINE GAAB: Often, we get hung up on the definitions. Or does the child have dyslexia? Or is it another reading disability? Maybe this child is only struggling because of environmental reasons or they were late talkers. There's all these different factors.

What's really important is that we find kids who struggle with reading early and help them early regardless of what the underlying cause is. And whatever diagnosis we give the child should be the one that helps them most within the systems they're living in.

JILL ANDERSON: We're going to talk a bit more about early screening and early intervention, but is there some sort of paradox between what we know in brain science about dyslexia and intervention versus what's actually happening on the ground in schools?

NADINE GAAB: Yes. The biggest problem right now is that, when it comes to learning differences such as dyslexia, we are largely focused on a reactive deficit-driven wait to fail model instead of the development of preventative approaches. So let me explain it a little bit more.

So as a society, we embrace preventative medicine, right? So we love vaccines and checkups. And we get mammograms. We all do this so that we don't get sick.


NADINE GAAB: So we are trying to do this preventative angle. We don't do that as much in education, where we more or less have the kids start school. Then we kind of observe who is struggling. And we observe a little bit more and observe a little bit more. And there may a bit of response to intervention, et cetera, et cetera. But overall, it's more a wait to fail model than it is a preventative model.

What we knew since probably the last 25 years is that the brains of children who are struggling with reading, including dyslexia, show some alterations. So their brain development is different from children who don't struggle with learning to read. What we didn't know for the longest time is whether this is a result of struggling on a daily basis since kindergarten.

So is it that they all kind of start the first day of kindergarten with a clean slate when it comes to brain development, and then the brain changes because they're struggling on a daily basis? Or do these brain alterations predate the onset of formal reading instruction? And what we could show is that some of these brain alterations are already there in infancy, and toddlerhood, and preschool.

So what we can conclude from this is that some children step into their first day of kindergarten with a less optimal brain for learning to read. So you want to find them right then, right? And that has tremendous implications for policy. You don't want to wait and let them fail if you already can determine who will struggle most likely and who will not.

JILL ANDERSON: When you hear that, the obvious question becomes, why has it been so hard to implement some form of earlier screening if we already know that many children can get early intervention and change the outcomes?

NADINE GAAB: Yeah. It's really a problem on the systems level, right? I want to just emphasize that we can't use brain imaging on the individual basis to determine this child will develop dyslexia and this child will not. And I don't think that's where we want to go, but we behaviorally know. In 3 and 4-year-olds, we can reliably identify based on a series of prereading tasks and milestones who will most likely struggle with learning to read.

But the educational system is not really a preventative system as we have in medicine. And I think it just takes a shift in mindset in order to move from that wait to fail model to a more preventative lens. And we need to make sure that we look into prekindergarten and other preschool educational settings. We need to train teachers in order to understand these milestones and being able to recognize, being able to intervene early.

So there's a lot of different levels related to policy, related to how we currently operate in terms of literacy development, and how early literacy development starts. So most people still think it starts maybe late preschool or midpreschool. But in my lab, we know that literacy development starts in utero because the fundamental milestones for learning to read are sound and language processing. And they start as early as in utero.

JILL ANDERSON: Wow. I mean, hearing all of this makes me think this is a huge issue. And there's so many layers to it. So we're seeing movement on one end in that many more states have begun to mandate universal dyslexia screening in children between kindergarten and second grade.


JILL ANDERSON: And that's a big step forward, but it sounds like that's still not necessarily going to be enough to respond and help these kids.

NADINE GAAB: Yeah. So there's many, many more layers to this. It's definitely a really good first step that we now have, that early screening legislation in most states in the United States. But often, educators don't know what kind of screeners to use. They don't know how to interpret the screening results. 

So there's the lack of data literacy in many educational settings is a problem. But also, often pre-K, kindergarten, first grade teachers are not trained to intervene and remediate some of these early signs that these screeners pick up. And so that's where higher education needs to come in where we need to have teachers learn these kinds of things in their teacher training.

Another set of issues is related to having assessments that are working well for multilingual learners, for dialect speakers, that are really culturally responsive and inclusive. And so there's many different layers to follow now. We can't just lean back and say, now we have legislation and everything. We'll automatically move to a more preventative model in education.

JILL ANDERSON: If you could snap your fingers and just change everything instantly, what do you think it would look like to have that preventative model in place? It would start in utero it sounds like.

NADINE GAAB: Yeah. So I think it's really important that we shift our mindset and say that reading development starts in utero, right? So if we think about this, then after the child is born the next steps of successful reading development are all within the framework of oral language, right?

So the child learns to distinguish which sounds belong to her or his or their native language versus other languages. We learn the meaning of the words and the rules of our language. And then years later, we learn to map the sounds of our language or languages onto the graphemes and start putting those together and start decoding. The ultimate goal is to read paragraphs and comprehending what you read.

So if you see reading development as a very complex skill that starts in utero and develops all the way into late adolescence or adulthood and that we recognize that it needs a lot of explicit instruction and practice, I think that will bring us a long way. Because what that means is that, if we place reading development as starting in utero, then the first four, four and a half years of reading development are actually oral language development.

So if we think about early identification, if you think about how can we prepare children for successful reading acquisition, we want to focus as much on the oral language component, listening, comprehension, vocabulary, as much as on the mechanics of learning to read. So learning the letters, the sounds of the letters, and decoding, morphology, et cetera.

JILL ANDERSON: And we know-- one of the things I know from hosting the EdCast is just how we teach reading is such a hotly debated subject in America. I mean, it comes up regularly in episodes. Anything that has to do with literacy, it seems to come up. Because that's just something that not everyone seems to agree on. And not that I want to take us down a path of talking about the reading wars today.

NADINE GAAB: Thank you.

JILL ANDERSON: But it seems like that kind of plays into this.

NADINE GAAB: Yeah. I'm a little bit more optimistic. I think we have the science of reading. And I think we need to understand what the science of reading is and what it's not, right? So what it's not is it's not some ideology or philosophy. And it's not a political agenda, or a certain program of instruction, or a single specific component of instruction such as phonics.

What it really is is the interdisciplinary body of all the scientifically-based research that many, many people around the globe have done over 50 years. And now, what we do is we are taking that body of knowledge and applying it into the school systems. And so the translational component is difficult as we know from many other disciplines.

And so I think we should see similar to climate, right? So we didn't know as much about climate changes. But now, we do. And there is a vast interdisciplinary body. And now, we have to implement it into policy changes and systems level changes. And we have to do that in reading as well.

So I see it very optimistic. We just need to start fighting and working together and bringing the different strands together, which includes the oral language piece and background knowledge as well as the mechanics of reading. So I think if we just manage to put it all together, it will be a really good addition to the field and will eventually, hopefully, move these reading scores up.

JILL ANDERSON: When I think about that data of approximately 65% of all fourth graders are not reading at grade level, I try to imagine what would that look like if we had some early intervention in place to actually identify challenges kids may have or learning disabilities that kids may have.

NADINE GAAB: Yeah. I mean, 65% of fourth graders are not reading at grade level. But I think it's important to mention that not 65% of these fourth graders have dyslexia, right? There's many—


NADINE GAAB: --different factors that contribute to atypical reading development. So you have genetics. You have brain development. You have perception and cognition. And you have the environment, right? 

Many years ago, I think the field thought, if you just find this one cause of dyslexia, we can just work on it. And then all children will miraculously read well. But I think the field has long moved away from this and now sees the multifactorial aspects and how these factors interact with each other.

I think what we need to do is really work on all of these components, so environmental factors such as neighborhood factors and stress related to maybe chronic illness of the parent, immigration status, socioeconomic status, trauma, et cetera, et cetera. We've had many good policies put in place. So we had the National Reading Panel, and No Child Left Behind, and the Individuals with Disabilities Education Act, and Decoding Dyslexia, and other aspects.

But that really has not moved the needle much if you look at the National Center for Education Statistics. So it's not that these 65% are suddenly showing up and we were reading fine 20 years ago or before COVID, right? No. It's been low all the way back to the '90s.

And so I think we need to really think, based on the science we now know, what are some of the things we are missing. And so I think moving to a preventative model and seeing reading development similar to math, or executive functioning, or social emotional learning happening much, much earlier than we currently think they are. And so with that lens into infancy and early childhood and thinking about early identification and who is teaching these children early and how much are they appreciated in the educational system and their training and compensation will really move the needle in my opinion. It's not going to be the only thing, but I think it will be a really important piece.

JILL ANDERSON: In the meantime, we have parents, caregivers. They often seem to be the folks who are really working on this at least within their schools. They're trying to get services that they need for their kids. And it seems like in a lot of ways, even with a lot of the mandated screening, the parents and advocates are the people who are pushing this forward in a lot of ways. What is your advice to them as they wait for either more legislation or wait for some more change to take place?

NADINE GAAB: I think parents have done or caregivers have done an incredible job in the last 10 plus years when it comes to reading disabilities, including dyslexia. My advice would be to know your rights, work with your educators, take an active role in your child's reading development, know what the milestones are, know how important home literacy is, but also work in a community setting. So we do a lot of work with pediatricians, and social workers, and libraries, and other stakeholders in the process.

And we think that, in order to optimize how we care for children who struggle with reading or have a learning disability is to really improve that working together on the systems level. That includes the general educator talking to the pediatrician, or it includes the advocacy of people in the community like after school teachers, and bus drivers, and maybe officials in churches and libraries to know more about learning disabilities and optimize care for children who are struggling and do this as early as possible.

And I think we often say, well, the educators don't give us access to screening, or they don't know. I think we have to give a lot of credit to educators who really want children to do well, but often they haven't been trained on prevention and early identification. That's not part of teacher training preservice. 

It's not often a big topic in higher education. And also, the quality of evidence-based professional development and how it's delivered is often suboptimal. So I feel like the whole system needs to change for us to embrace more of a preventative model.

And then I think what's also really important-- and I want to make sure we mention this-- is that we still don't know whether there are language-specific risk factors. We know now that we can screen multilinguals and dialect speakers and that they need to be included in the screening process, but that development of equitable screening tools and assessments and eliminating biases and reading curricula and screening early identification even in the intervention process or the support systems and awareness is really, really important.

So it really takes a whole village. And I know every child has the right to learn to read well. So we all have to work together in order to maximize the joy of learning to read.

JILL ANDERSON: Nadine, well, thank you so much. This was really eye-opening and informative.

NADINE GAAB: Thank you so much for having me today.

JILL ANDERSON: Nadine Gaab is an associate professor at the Harvard Graduate School of Education. She leads the Gaab Lab, which focuses on typical and atypical learning trajectories from infancy to adulthood with a special focus on language and reading development.

I'm Jill Anderson. This is the Harvard EdCast produced by the Harvard Graduate School of Education. Thanks for listening. 

Correction: The audio version of this podcast references an inaccurate statistic. The correct percentage of Americans with dyslexia is 5% to 10%.


An education podcast that keeps the focus simple: what makes a difference for learners, educators, parents, and communities

Related Articles