Early Identification of Language Delay
Philip S. Dale, PhD, Janet L. Patterson, PhD
Department of Speech & Hearing Sciences, University of New Mexico, USA
Because language is central to so many aspects of human life – cognition, social interaction, education and vocation – valid identification, prevention, and treatment of language disorders is a high priority for the therapeutic professions. Delay and/or difficulty in beginning to use language is one of the most common causes of parental concern for young children brought to pediatricians and other professionals. Delay may indicate specific difficulty with language, or it may be an early indicator of a broader problem such as developmental delay or autism.
In this article, we summarize current knowledge about the assessment of young children’s language below age 3, particularly in the range of 24 to 30 months (for which we have the most extensive information), in order to identify early language delay and/or risk for persistent language impairment. The goal of this screening process is to guide decisions concerning the need for further evaluation and treatment, in order to prevent the development of more significant problems. Language sampling and analysis have substantial time and expertise requirements.
Early identification of language delay must resolve two fundamental problems. The first is the problem of obtaining valid information at an age when children are often not sufficiently compliant for direct testing, especially those with limited communication skills who are the primary focus. Furthermore, the assessment technique must be cost-effective with respect to professional time, and broadly applicable across a range of social classes and language backgrounds, including bilingualism. Language sampling and analysis have substantial time and expertise requirements.
The second problem is one of interpretation. Many children whose language is delayed at 24 or 30 months will catch up over the next few years, and do not warrant intervention.1 The challenge is to identify and use other relevant information to improve decisions about individual children.
The solution to the first problem above has been the revival of an older, but neglected technique: parent report.2,3 Parents have much more experience with their children than professionals, and their experience is more representative of their child’s experiences and interests. Vocabulary checklists and related questions for parents have proven to be highly valid measures of early language development.4,5,6,7,8,9,10
Solving the second problem has required two programs of research: first, large-scale norming studies to provide a basis for judgment of the relative status of a child’s language (delayed or not)3 and second, longitudinal studies of outcome of early delay to identify predictors of “spontaneous recovery” or continued delay.1
Key Research Questions
Five questions are central to early identification of language delay:
- What is a valid criterion for defining early language delay?
- How much variability in outcome is there for early delay?
- What other factors can add to prediction of outcome, and how should they be integrated?
- How do differences related to social class, gender, and ethnicity affect the identification process?
- How should the process be modified for children acquiring two or more languages?
Recent Research Results
Toddlers who have not attained the expressive language skills exhibited by most children the same age can be identified as having slow expressive language development (SELD). Among English-speaking children, studies suggest that 90% of 24-month-olds have an expressive vocabulary of at least 40-50 words and about 85% are combining words.6 Based on these findings, two criteria for identifying SELD among 24-month-olds are commonly used: 1) small expressive vocabulary (less than 40-50 words, or below the 10th percentile, depending on the tool used) and/or 2) no word combinations.6,8 The 10th percentile criterion can be extended to other ages.
Children with SELD at age 2 are at 2 to 5 times higher risk for language impairment persisting into the late preschool to elementary school years than children without SELD.1,11 Even though at least half of the two-year-olds with SELD will have language skills that are within the normal range by school age,9,10 early expressive language delays should not be ignored, given the elevated risk of persisting language impairment.
Longitudinal studies of two-year-olds with SELD have examined a variety of potential predictor variables for persisting difficulties. Those variables which most regularly are found to make some prediction include parent concern about possible problems with the child’s speech/language development or hearing, family history of language impairment or dyslexia (especially first degree relatives: parents, full siblings), receptive language delays, frequent ear infections, limited vocalizations, and delayed pretend play.12,13,14 Although none of these is a highly accurate predictor by itself, parental concern has been the most consistently associated with language impairment.1,10 Combining predictors has improved accuracy of predictions, but the optimal combination of predictors is not yet known.
For monolingual children who speak languages other than English, there are adaptations of the widely used MacArthur-Bates Communicative Development Inventories (CDI)a and the Language Development Survey (LDS)8,16,17 in a number of languages. There is considerable consistency across languages in children’s early expressive language development. For example, word combinations are reported for about 85% of Spanish-speaking and over 90% of French-speaking 24 to 26-month-olds children.15,18
Bilingual children’s development of expressive vocabulary is comparable to monolingual children when parent reports for both languages are obtained and combined. There are two methods for combining vocabulary scores: “Total conceptual vocabulary (TCV),” in which words with similar meanings (e.g., English “cat” and Spanish “gato”) are counted only once,19 and “Total vocabulary (TV)” which includes all words in each language, regardless of possible overlap in meaning. For young children, TV (Language A + Language B) is recommended because it is simple to calculate and it yields vocabulary size scores and growth rates for young bilingual children that are similar to those for monolingual children’s vocabulary.20 Age of onset of word combinations also is similar for bilingual and monolingual children if bilingual children are credited with combining words if they do so in either language.16,21,22,23
Although pairs of monolingual forms can be used, there are also some bilingual adaptations of vocabulary checklists available, including Spanish-English22 and German-English16 adaptations of the Language Development Survey and a bilingual Spanish-English scoring adaptation of the CDI.21
Variation in findings across social groups and gender differences indicates that parent report tools and/or criteria for early identification may need adjustment for different populations. The rate of identification of SELD using parent report tools is much higher for children from lower SES families; cut-offs that yield about 10% of middle class children identify two to three times as many children from lower SES backgrounds.24 Although children from low SES backgrounds are at somewhat higher risk for language impairment, these major differences in rate of identification raise concerns about over-identifying SELD among children from lower SES backgrounds. Children from minority ethnic backgrounds had lower average scores when SES was controlled for in one study, raising similar questions about the validity of parent report tools in culturally diverse populations.24 Finally, when uniform expressive vocabulary and word combination criteria are used, more 2-year-old boys are identified with SELD,1,11,25 raising a question of whether different criteria may be appropriate for boys and girls. Research comparing outcomes for boys and girls with SELD is needed to address this question.
Young children with expressive language skills that are approximately below the 10th percentile are at much higher risk than peers for persisting language or even broader developmental problems, even though there is a wide range of outcomes and many children with SELD at two years of age are in the average range by four years of age. A variety of additional variables are associated with persisting delays, and parental concern about possible speech-language problems is a key predictor of risk for language impairment.
Early childhood educators, health care providers and other professionals can identify risk for language impairment in young children based on parent-reported information. Immediate referral to a speech-language pathologist is recommended for children with slow expressive language development if the parents are concerned that the child has possible speech-language problems or when there are additional risk factors. On the other hand, if the parents are not concerned about the child’s speech-language development and there are no additional risk factors, monitoring (“watchful waiting”) is recommended for children who are not combining words or who have a small expressive vocabulary (under 40 words) at 24 months.
Monolingual children who speak languages other than English should be referred for evaluation if they are delayed in expressive vocabulary and onset of word combinations in their native language. Because expressive language development is comparable among monolingual and bilingual children when bilingual children’s development in both languages is taken into account, bilingual two-year-olds who are not combining and/or have small total expressive vocabularies should be monitored and/or referred for further evaluation.
Collaborative efforts between practitioners and researchers on large scale screening programs that combine screenings with follow-up evaluations are needed to refine and validate models for predicting persisting language impairment for children with parent-reported SELD, using other information about the child and family. These efforts should also include work to adapt, implement and validate measures for children from homes in which languages other than English are spoken, and for children from lower socioeconomic backgrounds.
- Dale PS, Price TS, Bishop DVM, Plomin R. Outcomes of early language delay: I. Predicting persistent and transient language difficulties at 3 and 4 years. Journal of Speech, Language, and Hearing Research 2003;46(3):544-560.
- Dale PS. Parent report assessment of language and communication. In: Cole KN, Dale PS, Thal DJ, eds. Assessment of communication and language. Baltimore, MD: P.H. Brookes;1996:161-182.
- Fenson L, Dale PS, Reznick JS, Bates E, Thal DJ, Pethick SJ, eds. Variability in early communicative development. Monographs of the Society for Research in Child Development 1994;59(5):1-173. Theme issue.
- Dale PS. The validity of a parent report measure of vocabulary and syntax at 24 months. Journal of Speech and Hearing Research 1991;34(3):565-571.
- Dale PS, Bates E, Reznick JS, Morisset C. The validity of a parent report instrument of child language at twenty months. Journal of Child Language 1989;16(2):239-249.
- Fenson L, Marchman VA, Thal DJ, Dale PS, Reznick JS, Bates E. MacArthur-Bates Communicative Development Inventories: User’s guide and technical manual. 2nd Ed. Baltimore, Md.:Paul H. Brookes Pub. Co;2007.
- Feldman HM, Dale PS, Campbell TF, Colborn DK, Kurs-Lasky M, Rockette HE, Paradise JC. Concurrent and predictive validity of parent reports of child language at ages 2 and 3 years. Child Development 2005;76(4):856-868.
- Rescorla L. The language development survey: A screening tool for delayed language in toddlers. Journal of Speech and Hearing Disorders 1989;54(4):587-599.
- Guiberson, M., Rodriguez, B. L., & Dale, P. S. Classification accuracy of brief parental report measures of language development in Spanish-speaking toddlers. Language, Speech, and Hearing Services in Schools 2011;42, 536-549.
- Klee T, Pearce K, Carson DK. Improving the positive predictive value of screening for developmental language disorder. Journal of Speech, Language, and Hearing Research 2000;43(4):821-833.
- Rice ML, Taylor CL, Zubrick SP. Language outcomes of 7-year-old children with or without a history of late language emergence at 24 months. Journal of Speech, Language, and Hearing Research 2008;51(2):394-407.
- Ellis E, Thal D. Early language delay and risk for language impairment. Perspectives on Language Learning and Education 2008;15(3):93-100.
- Olswang L, Rodríguez B, Timler G. Recommending intervention for toddlers with specific language learning difficulties: We may not have all the answers, but we know a lot. American Journal of Speech-Language Pathology 1998;7:23-32.
- Lyytinen P, Eklund K, Lyytinen H. Language development and literacy skills in late-talking toddlers with and without familial risk for dyslexia. Annals of Dyslexia 2005;55(2):166-192.
- Jackson-Maldonado D, Bates E, Thal D. MacArthur Inventarios del Desarrollo de Habilidades Comunicativas: User’s guide and technical manual. Baltimore, MD: P.H. Brookes;2003.
- Junker D, Stockman I. Expressive vocabulary of German-English bilingual toddlers. American Journal of Speech-Language Pathology 2002;11(4):381-394.
- Papaeliou, C. & Rescorla, L. Vocabulary development in Greek children: A cross-linguistic comparison using the Language Development Survey. Journal of Child Language 2011;38, 861-877.
- Trudeau, N. & Sutton, A. Expressive vocabulary and early grammar of 16- to 30-month-old children acquiring Quebec French. First Language 2011;31, 480-507.
- Pearson B, Fernández S, Oller K. Lexical development in bilingual infants and toddlers: Comparison to monolingual norms. Language Learning 1993;43(1):93-120.
- Core, C., Hoff, E., Rumiche, R., & Señor, M. Total and conceptual vocabulary in Spanish-English bilinguals from 22 to 30 months: Implications for assessment. Journal of Speech, Language, and Hearing Research 2013;56, 1637-1649.
- Marchman V, Martínez-Sussman C. Concurrent validity of caregiver/parent report measures of language for children who are learning both English and Spanish. Journal of Speech, Language, and Hearing Research 2002;45(5):283-997.
- Patterson JL. Expressive vocabulary development and word combinations of Spanish-English bilingual toddlers. American Journal of Speech-Language Pathology 1998;7:46-56.
- Hoff, E., Core, C., Place, S., Rumiche, R., Señor, M., & Parra, M. Dual language exposure and early bilingual development. Journal of Child Language 2012;39, 1-27.
- Rescorla L, Achenbach T. Use of the Language Development Survey (LDS) in a national probability sample of children 18 to 35 months old. Journal of Speech, Language, and Hearing Research 2002;45(4):733-743.
- Rescorla L, Alley A. Validation of the Language Development Survey (LDS): A parent report tool for identifying language delay in toddlers. Journal of Speech, Language, and Hearing Research 2001;44(2):434-444.
a See also the MacArthur-Bates Communicative Development Inventories website. Available at: http://mb-cdi.stanford.edu/. Accessed February 15, 2017.
How to cite this article:
Dale PS, Patterson JL. Early Identification of Language Delay. In: Tremblay RE, Boivin M, Peters RDeV, eds. Rvachew S, topic ed. Encyclopedia on Early Childhood Development [online]. http://www.child-encyclopedia.com/language-development-and-literacy/according-experts/early-identification-language-delay. Updated February 2017. Accessed December 14, 2017.