Abstract

Early-life musical engagement is an understudied but developmentally important and heritable precursor of later (social) communication and language abilities. This study aims to uncover the aetiological mechanisms linking musical to communication abilities. We derived polygenic scores (PGS) for self-reported beat synchronisation abilities (PGSrhythmicity) in children (N≤6,737) from the Avon Longitudinal Study of Parents and Children and tested their association with preschool musical (0.5-5 years) and school-age (social) communication and cognition-related abilities (9-12 years). We further assessed whether relationships between preschool musicality and school-age communication are shared through PGSrhythmicity, using structural equation modelling techniques. PGSrhythmicity were associated with preschool musicality (Nagelkerke-R2=0.70-0.79%), and school-age communication and cognition-related abilities (R2=0.08-0.41%), but not social communication. We identified links between preschool musicality and school-age speech-and syntax-related communication abilities as captured by known genetic influences underlying rhythmicity (shared effect β=0.0065(SE=0.0021), p=0.0016), above and beyond general cognition, strengthening support for early music intervention programmes.

Abstract

Mastering developmental milestones such as infant motor and personal-social skills (including social routines and pretend-play) can initiate a cascade of developmental changes that may affect language learning. Specifically, motor development may represent an important, but little understood “gateway” enabling children to interact with their environment. Here, we investigate how infant motor and personal-social abilities link to infant and toddler language performance, using a genetic perspective. For this, we studied measures of motor and personal-social skills (6 and 15 months) as predictors of language development, captured by ten language phenotypes (15-38 months) in genotyped children from the Avon Longitudinal Study of Parents and Children (N≤7,017). Language measures were combined into language factor scores (LFS) using structural equation modelling. Developmental genomic and non-genomic (residual) relationships across phenotypes were modelled with a Cholesky decomposition using genetic-relationship-matrix structural equation modelling (GRM-SEM). The ten early language measures were captured by three interrelated language factors (F-15M, F-24M, F-38M, 51.3% explained variance), each corresponding to a different age window. Across infant predictors and derived language factor scores, common genetic variation accounted for a modest proportion of the phenotypic variance (known as heritability, h2: gross-motor-abilities-6M-h2=0.18(SE=0.06), personal-social-skills-15M-h2=0.18(SE=0.06), LFS-15M-h2=0.12(SE=0.05), LFS-24M-h2=0.21(SE=0.06), LFS-38M-h2=0.17(SE=0.05)). Fitting a Cholesky GRM-SEM across predictors and LFS showed that infant gross motor abilities shared genetic influences with personal-social skills (factor loading λ; personal-social-skills-15M-λ=0.22(SE=0.09)), but were unrelated to language performance (P≥0.05). In contrast, genetic influences underlying personal-social skills, independent of gross motor skills, were related to all three LFS (LFS-15M-λ=0.26(SE=0.09), LFS-24M-λ=0.28(SE=0.10), LFS-38M-λ=0.30(SE=0.10)). GRM-SEM analyses studying individual language outcomes provided consistent results, both for genomic and non-genomic structures. Thus, aetiological processes linking motor to personal-social skills differ from those linking personal-social to language abilities, consistent with a developmental cascade where motor control enables children to engage in novel social interactions, but children’s social learning abilities foster language development.