Meta-analysis of receptive and expressive language skills in autism spectrum disorder Elaine Y.L. Kwok a , Heather M. Brown b , Rachael E. Smyth c , Janis Oram Cardy a,c, * a School of Communication Sciences and Disorders, University of Western Ontario, Elborn College, London, Ontario, Canada N6G 1H1 b Department of Psychology, University of Western Ontario, Westminster Hall, London, Ontario, Canada N6A 3K7 c Graduate Program in Health and Rehabilitation Sciences, University of Western Ontario, Elborn College, London, Ontario, Canada N6G 1H1 1. Introduction Impairment in communication for social purposes is a hallmark feature of autism spectrum disorder (ASD; American Psychiatric Association, 1994). Impairment in the understanding and use of language (i.e., in receptive and expressive language functioning) is more variable across the population, but is fairly common (Bishop, 2010; Kjelgaard & Tager- Flusberg, 2001). For example, Loucas et al. found that roughly 57% of their sample of children with ASD and normal non-verbal intelligence had language impairments. Although many studies of children with ASD have included Research in Autism Spectrum Disorders 9 (2015) 202–222 A R T I C L E I N F O Article history: Received 29 July 2014 Received in revised form 9 October 2014 Accepted 10 October 2014 Available online 19 November 2014 Keywords: Autism spectrum disorder Language Expressive Receptive A B S T R A C T Clinical anecdotes suggest that children with autism spectrum disorder (ASD) often show an atypical language profile in which expressive language exceeds receptive language competency. However, the few studies to directly explore this language profile have yielded inconsistent findings. This meta-analysis examined 74 studies that reported the receptive and expressive language performances of children and youth with ASD. Four potential predictors (age, language domain, source of language data, method of ASD diagnosis) were separately analyzed for their contribution to the relative receptive and expressive language impairment in ASD. Contrary to popular belief, the current meta- analyses found no evidence that an expressive advantage is common in ASD. Overall, children and youth with ASD showed equally impaired receptive and expressive language skills, both falling roughly 1.5 SD below peers with typical development. No discrepancies were found in receptive and expressive language across developmental stages, cognitive abilities, vocabulary, global language skills, caregiver report measures, clinician- administered measures, mixed method measures, or method of ASD diagnosis. Although some individual children with ASD may have an expressive-better-than-receptive language profile, this profile is not common enough to be a useful marker of ASD. ß 2014 Elsevier Ltd. All rights reserved. * Corresponding author at: School of Communication Sciences and Disorders, University of Western Ontario, Elborn College, London, Ontario, Canada N6G 1H1. Tel.: +1 519 661 2111x88000; fax: +1 519 850 2369. E-mail addresses: ekwok5@uwo.ca (Elaine Y.L. Kwok), heather.brown@alumni.uwo.ca (H.M. Brown), rsmyth5@uwo.ca (R.E. Smyth), janis.cardy@uwo.ca (J. Oram Cardy). Contents lists available at ScienceDirect Research in Autism Spectrum Disorders Jo u rn al h om ep ag e: h ttp ://ees .elsevier .co m /RASD/d efau lt.as p http://dx.doi.org/10.1016/j.rasd.2014.10.008 1750-9467/ß 2014 Elsevier Ltd. All rights reserved.