The MSCA-GF Linguistic Illusions project focuses on the linguistic development of Southern African American English-speaking (AAE) and Southern English-speaking (SE) children (aged 2–13) with either typical language development (TLD) or Language Disorder (LD), as well as individuals with Down syndrome (DS) starting at age 4. The AAE and SE varieties are socially stigmatized, despite previous work showing that what is often misperceived as lack of grammatical knowledge, especially the reduction of overt inflection when compared to Mainstream American English (MAE), is in fact a characteristic of the varieties (MAE: John wants cake. vs. AAE: John want cake). Similar characteristics have also been reported for DS and LD. The main research objective of this project was to provide the first comparative examination of language acquisition in SE and AAE in the 3 populations we set out to study. Empirically, we aimed to achieve an unbiased description of the data for a more inclusive analysis, and eliminate external factors that may affect our results such as dialectal particularities. Our second empirical objective concerned the formulation of developmental trajectories (DT) (i.e. the course of development with various grammatical elements) for the 3 populations, which will help determine if a child’s development is as expected, based on the population, age, and linguistic variation, or if and in what way it deviates. Our clinical objective was to use the DTs as a guide to provide a speedier, and more targeted diagnosis and create better-informed intervention plans.
Results from almost 300 AAE- and SE- speaking children (TD, DS, and LD) from the Southern State of Mississippi show significant differences across the 3 populations and suggest a serious problem of astoundingly high risk for LD for the TLD populations (SE: 37.6% & AAE: 60.5%) that has never, to the best of our knowledge, been reported for any language or linguistic variety. After considering numerous possibilities, we concluded that gaps in the acquisition of grammar created by limited education and/or exposure to language before the age of 5 ‘allow’ the diagnostic test to over-screen and produce false-positives. Note that percentages of grammaticality were in fact high (87%-99.8%), with one exception. Additional customized and standardized testing confirm this conclusion. It should also be noted that 95% of children that were identified as being at risk for LD did not have a prior diagnosis, though they were at an age where they should have been tested or identified. Neither age nor the parents’ educational level was proven reliable factors for predicting either variation from MAE or risk for LD.
This project makes numerous contributions on a linguistic, methodological, clinical, and social-outreach level. For example, it enables us to clarify which seemingly grammatical differences between what is expected and what is actually produced are due to differences in the variation of English our participants are speaking and which are grammatical errors, which, in turn, prevents misdiagnosis and facilitates early diagnosis and intervention. Results from this study can assist with social inclusion of individuals with DS and LDs, as well as AAE-speaking children, given that AAE is a socially stigmatized variety. Our numerous outreach initiatives with public events, media coverage, and educational workshops for the public, conference presentations, and journal publications also help improve the public’s opinion on individuals with DS, LDs as well as the grammatical standing of dialects. The number of participants, populations, age range, grammatical phenomena, and the number of tasks administered are all innovative additions to the limited information available on these variations of American English.