Developmental changes in frequency, flexibility, length, and contextual aspects of echolalia in neurotypical children

Echolalia is a common phenomenon in early language development, but there are very few studies on immediate echolalia in neurotypical (NT) children. Because this repetitive and stereotyped behavior is considered one of the hallmarks of autistic children, professionals often need to differentiate between typical, developmental echolalia and the increased repetitive, stereotyped behavioral characteristic often seen in autistic children. This study aimed to determine developmental changes in the characteristics of immediate echolalia in one- to three-year-old NT children. We present longitudinal data from spontaneous speech samples collected from three NT children aged 1-3 years (130 recordings in total). Developmental changes in the frequency of echolalia over time, the proportion of echolalia in total language production, the flexibility of echolalic utterances and their length, and the linguistic context of echolalia occurrence, i.e., parental utterances before and after the occurrence of echolalia, were analyzed. The findings revealed great variability in the frequency of echolalia, with a general peak at approximately 1;3-1;5. During this period, a high frequency of echolalia (30%) was observed in one child, suggesting that the frequency of echolalia in NT children may be significant at early age. However, a significant decrease in echolalia was observed up to the age of 2;6 years, and the incidence was extremely low thereafter (below 5%). In our sample, echolalia was characterized by the selective shortening of utterances, and it occurred more frequently after low-constraint utterances. This study provides novel insights into typical language development and guidelines for clinical work.