Characterizing the Language Phenotype in Adults with ASD and Its Relationship with Daily Living Skills

Background: Past research has focused primarily on the language phenotype in children with ASD, with only minimal work on language in adults. In particular few studies have examined multiple methods of assessing language (e.g., language sample vs. parent report). Additionally, there is a lack of research on the impact of the language phenotype on daily living skills in adults with ASD. 

Objectives: The primary aim of the present study was to characterize the language abilities of adults with ASD, using an interview-style language sample as well as parent report, and to examine the relationship between these variables and daily living skills.

Methods: We tested a sub-set of adults with ASD drawn from a larger study. An interview-style language sample and IQ test (Wide Range Intelligence Test; Glutting, Adams, & Sheslow, 2000) were completed with 85 adults with ASD, mean age = 26 years, mean IQ = 87. However, of the 85 individuals only 18 provided enough language within the language sample for a meaningful analysis. Of these 18 individuals, the majority were males (72%), with an average age of 25 years. The general IQ was quite high, although there was a broad range in this small sample (M = 134.39, SD = 216.49); verbal IQs were on average 51 points lower (M = 83.28, SD = 18.92). Parents reported on their son or daughter’s daily living skills using the Waisman Activities of Daily Living (W-ADL) Scale, and completed the Vineland Screener (Sparrow, Carter, & Cicchetti, 1993).

Interviews were transcribed using standard language transcription procedures, and analyzed using the Systematic Analysis of Language Transcripts (SALT; Miller & Chapman, 2000). Transcripts were analyzed for standard language measures including number of utterances, number of words, grammatical complexity, and measures of dysfluencies (e.g., repetitive speech, incomplete sentences).

Results: The adults who were able to complete the interviews demonstrated complex, and appropriate language abilities with few word and utterance level errors. However, they had a significant number of language dysfluencies, including repetitions (e.g., I went to went to the store yesterday), and revisions (e.g., The girl, I mean the man left). The language measures were not related to gender, age or IQ. The dysfluency measures were significantly related to the scores from the Vineland Screener, (e.g., a negative relationship between one of the measures of dysfluency (i.e., revisions) and the daily living standard score, r = -.56*, and social skills, r = -.52*). However, the language measures were not significantly related to the W-ADL scores.

Conclusions: The adults with ASD in this sample who were able to complete the language sample task were using complex language, marked by frequent dysfluencies. This was not related to overall cognitive abilities, but was in fact associated with daily living and social skills. Understanding the nature of the adult language phenotype and its impact on daily life will help guide practitioners in their treatment of language disorders in children and adolescents.