Why Preschool is a Critical Window for Language and Literacy Intervention
Why Preschool Is Not Early Intervention—It’s Critical Intervention
We often hear the term early intervention, and for good reason. Early experiences shape a child’s development in profound ways. But when it comes to children ages 3 to 5, “early” can be misleading. This stage isn’t a head start. It’s a make-or-break window.
Preschool is not the beginning, but rather the bridge between foundational brain development and formal learning. For children with communication delays, these years offer a powerful opportunity to intervene before gaps widen.
The Science: Why Ages 3–5 Matter So Much
By age 5, a child’s brain is about 90% developed in volume. This doesn’t mean development is done, but it does mean that the wiring for key skills—like language, attention, memory, and regulation—is rapidly forming.
Language development during this period plays a foundational role in:
Vocabulary growth
Reading readiness
Social communication and peer relationships
Emotional regulation
School success
Research shows that a child’s oral language skills between ages 3–5 strongly predict later reading comprehension and academic achievement (Snow & Dickinson, 2001).
The Risk of Waiting
Families and professionals are sometimes encouraged to “wait and see,” especially with late talkers or children who seem shy or quiet. But we now know that:
50–70% of toddlers with delayed speech who don’t receive early intervention continue to struggle with language and literacy in elementary school (Rescorla, 2005).
Children who enter kindergarten with lower oral language skills are more likely to face reading difficulties and need long-term academic support.
Waiting until school age often means intervening after problems have taken root, rather than preventing them in the first place.
What the Research Says About Preschool Intervention
Evidence is clear: targeted intervention in the preschool years improves language outcomes and school readiness. In a randomized controlled trial, toddlers who received responsive language-focused intervention showed gains in vocabulary, sentence structure, and engagement (Roberts & Kaiser, 2015).
Additional studies show that preschool speech and language services can enhance:
Expressive and receptive language skills
Phonological awareness
Narrative skills
Social participation
And these gains don’t just help in the moment—they lay the foundation for success in reading, writing, and learning throughout school.
What Effective Support Looks Like
Preschool intervention doesn’t have to mean drill-based instruction. In fact, the most effective strategies are embedded in play, relationships, and everyday routines.
Key features of critical intervention during ages 3–5 include:
Play-based learning that builds joint attention and symbolic language
Language-rich routines like snack time, cleanup, and transitions
Collaborative coaching with families, educators, and caregivers
Early literacy support using dialogic reading and phonological play
Neurodiversity-affirming practices that value multiple ways of communicating
When SLPs, caregivers, and teachers work together with intention during these years, they set children up for long-term success, not just in school, but in life.
Final Thoughts
Ages 3–5 are not early. They are critical.
This is the window where language meets learning, where brain development meets opportunity.
For children with communication delays, the preschool years offer the best chance to make meaningful gains before formal academics begin. Rather than waiting and hoping for things to resolve on their own, we can lean in with support that’s responsive, evidence-based, and relationship-centered.
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Snow, C. E., & Dickinson, D. K. (2001). Starting Out Right: A Guide to Promoting Children’s Reading Success. National Academies Press.
Rescorla, L. (2005). Age 17 language and reading outcomes in late-talking toddlers. Journal of Speech, Language, and Hearing Research, 48(2), 459–472.
Roberts, M. Y., & Kaiser, A. P. (2015). Early intervention for toddlers with language delays: A randomized controlled trial. Pediatrics, 135(4), 686–693.
Shonkoff, J. P., & Phillips, D. A. (2000). From Neurons to Neighborhoods: The Science of Early Childhood Development. National Academies Press.
