The term was originally coined by Scarborough and Dobrich (1990) in their renowned article, “Development of children with early language delay” (Scarborough and Dobrich, 1990). The authors were trying to reconcile two slightly contradictory findings in the literature: that “late talkers” (“children with limited expressive vocabulary at 18-24 months” (Bishop et al, 2016)) often recover by age 5 or 6, and simultaneously, longer term studies showing that many experience residual language and literacy difficulties in later childhood and beyond.
Scarborough and Dobrich wondered whether apparent recovery followed by longer term difficulties might occur within the same child. As part of their research, they compared four children with “early language delay” and a control group of twelve children at ages two and a half and five, and then followed them up three years later. The language abilities of the first group seemed to naturally improve over time, and at age five they were judged to be “near normal”. However, when they were followed up in Year 2, three of the four had severe reading difficulties.
Scarborough and Dobrich (1990) thought that this could be explained by their theory of “illusory recovery”. They observed that the language of the typically developing children did not develop evenly, but in a stepwise manner, with a series of growth spurts and plateaus. They proposed that as most children reach a plateau, the “delayed” children may seem to “catch up” temporarily, only for their underlying difficulties to show up again at the next developmental stage.
The authors acknowledged that it would be difficult to generalize from their small sample, and some have contested their results. In a large scale study, Dale et al (2014) found that children with “early language delay” were at no greater risk of long-term difficulties than those without a past history, but with similar scores at age 4. There is now a consensus that early language skills are highly variable and outcomes are difficult to predict (Bishop et al, 2016).
Regardless, some children clearly do appear to catch up temporarily, only for their difficulties to re-surface later. As a secondary school Speech and Language Therapist (SLT), this got me thinking about my own students. Those who I see tend to fall into one of three camps: those with recognized difficulties, who have received statutory support throughout their schooling, those who saw an SLT when they were younger, only to be discharged as their difficulties “resolved”, and a final group who had never even been flagged up before.
I’m continually surprised by the numbers who show up in my office with severe language disorders, some having been discharged a few years earlier, and many having never been seen before. Can it be that so many struggling students were missed at primary school? Does Scarborough and Dobrich’s logic apply to some of these students? Or could there be other reasons why difficulties may seem to re-emerge at this point, or even emerge for the first time?
Scarborough and Dobrich were not the first to propose that language develops in a stepwise fashion. In Walter Loban’s (1976) groundbreaking longitudinal study, he followed 211 pupils from kindergarten into early adulthood and documented their progress. He observed a similar pattern beyond early childhood and into secondary school, although the exact stages depended on the measures he used.
For example, in terms of the average number of words used per communication unit, he noted that for his “random” group, a year of growth was almost always followed by a year of plateau, or what he also called a “consolidation phase”. There were even crossover points on some of his graphs, which seemed to show his low group catching up with his high group. Again, this was only true for certain measures, such as the number of dependent clauses used per sentence.
However, when Loban studied them further, he found that his high ability group’s writing samples were actually of much higher quality, despite the data looking similar. The ability to create multiclausal sentences may well be a sign of linguistic growth, but as children mature further still, they actually learn to be more concise, replacing cumbersome clauses with less frequent syntactic structures such as appositives, and infinitival phrases.
What Loban’s graph showed, then, was not the low group catching up as the high group reached a plateau, but rather, the high group reaching the next developmental stage which was characterized by different markers. How we read the data, and how we measure growth, then, is important.
Researchers in the field have cautioned how some assessment tools for older students only assess relatively basic skills. A student with more subtle difficulties is likely to be missed. Whilst these factors may contribute to some cases of “illusory recovery”, there are likely to be additional elements involved.
In Cheryl Scott’s article, “A Case for the Sentence in Reading Comprehension” (Scott, 2009), she argued that many reading comprehension difficulties are linked to sentences increasing in length and complexity throughout school. As students reach secondary school, they are expected to understand much harder written texts, with language beyond what they would encounter in casual conversation. It is no coincidence that many “poor comprehenders” emerge at this point.
(See my post for further information about the challenges of academic text, or “expository discourse”: https://secondaryschoolslt.wordpress.com/2026/04/15/what-is-expository-discourse-and-how-is-it-relevant-at-secondary-school/ .)
It may be, then, that some deficits are mild enough to go unnoticed throughout early childhood and the more informal context of primary school, only to become painfully apparent in the more serious environment of secondary school where expectations are much higher. Larson and McKinley (2003), too, observed that difficulties are likely to re-emerge as the linguistic and cognitive demands of a new context increase, such as in the transition to secondary school.
(For more information about the challenges of secondary school, please see my post: https://secondaryschoolslt.wordpress.com/2026/03/18/what-are-the-main-challenges-of-secondary-school-for-students-with-language-disorders/. )
Another confounding factor, is that whilst language disorders are chronic, they are not stable. So, an early difficulty with oral language may evolve into more of pragmatic difficulty, or a difficulty with reading and writing later on, as in the Scarborough and Dobrich study (1976). Someone with a surface level understanding may consider the initial language disorder resolved, only to be replaced by a separate reading difficulty.
It is more likely that these are different manifestations of the same, underlying condition. Some areas, such as vocabulary or basic syntax may improve due to internal shifts, or external factors such as successful intervention (hopefully!), only for other challenges to come to the fore for the reasons already discussed.
I hope to have shown how relevant the concept of “illusory recovery” is to older students. In my experience, many students arrive at secondary school with language disorders which were deemed to have “resolved”, or were never even picked up before. They may have seemed to have gotten better in the past due to successful intervention efforts, the naturally evolving nature of their condition, or possibly the use of inappropriate or insensitive assessment tools. Their underlying difficulties then appear to re-emerge with the increasing demands or secondary school, or possibly as other students move on from a developmental plateau, leaving them behind.
For more information on whether language disorders persist, please see my article:
Notes
Bishop DVM, Snowling MJ, Thompson PA, Greenhalgh T, CATALISE consortium (2016). CATALISE: A Multinational and Multidisciplinary Delphi Consensus Study. Identifying Language Impairments in Children. PLoS ONE 11(7): e0158753.
Bishop, D.V.M., Snowling, M.J., Thompson, P.A., Greenhalgh, T., and the CATALISE-2 consortium (2017). Phase 2 of CATALISE: a multinational and multidisciplinary Delphi consensus study of problems with language development: Terminology. Journal of Child Psychology and Psychiatry, 58(10), pp. 1068–1080.
Dale, Philip S., Andrew J. McMillan, Marianna E. Hayiou-Thomas, and Robert Plomin. “‘Illusory Recovery’: Are Recovered Children with Early Language Delay at Continuing Elevated Risk?” American Journal of Speech-Language Pathology 23, no. 3 (August 2014): 337–46.
Larson, V.L. and McKinley, N.L. (2003) Communication solutions for older students. Thinking Pub.
Loban, W. (1976) Language Development: Kindergarten through Grade Twelve. Urbana, IL: National Council of Teachers of English.
Scarborough, Hollis S., and Wanda Dobrich. “Development of Children with Early Language Delay.” Journal of Speech and Hearing Research 33, no. 1 (1990): 70–83.
Scott, Cheryl M. “A Case for the Sentence in Reading Comprehension.” Language, Speech, and Hearing Services in Schools 40, no. 2 (April 2009): 184–91.
Thoughts of a secondary school SLT 
Leave a comment