How bilingualism shapes (or does not) the socio-cognitive skills of autistic and neurotypical adults

Background: Research finds a positive influence of bilingualism on socio-cognitive skills for autistic and non-autistic children. However, findings in adulthood are inconsistent in neurotypical people and absent for autistic people. This study aims to chart the influence of bilingualism on cognitive and affective perspective-taking skills in autistic and neurotypical adults.Methods:We recruited 31 autistic (42% female, mean age = 33.2 years) and 95 neurotypical (72% female, mean age = 28.5 years) adults with a range of language exposures, who completed an executive attention task, and a socio-cognitive test battery. Stepwise multiple linear regressions were conducted to identify the influence of language exposures, proficiency and usage while controlling for age, attention, and non-verbal IQ variables.Results:Age of acquisition of the 2nd language negatively predicted cognitive (b = -0.020, p = 0.0012) and General (b = -0.020, p = 0.0036) perspective-taking scores above and beyond the other control variables for a range of tested socio-cognitive outcomes, but not Affective perspective-taking scores.Conclusions: This study describes a long-lasting developmental stimulating influence of early bilingualism on key sociocognitive processes in autistic and neurotypical adults alike, above and beyond the role of other individual differences such as non-verbal IQ or executive skills.