A Network Approach to Developmental Differences and Disorders

Child and adolescent development is influenced by complex interplay between a range of diverse factors. The network approach is gaining popularity as a way of modelling such complex processes. Here we used the network approach to investigate whether developmental differences and disorders can be conceptualised as arising from direct interactions between different areas of psychological functioning. We used data from four population-based birth cohorts in England (n=47,315), those born in the 1970s, 1990s, and 2000s, to investigate interrelations between areas of psychological functioning that underpin learning and engagement in educational settings (i.e., memory, attention, non-verbal ability, arithmetic skills, reading, language and communication, motor skills, neurodevelopmental characteristics, psychopathology, social functioning, and wellbeing). We fitted 12 undirected psychometric network models; one network for each cohort and developmental stage (early childhood; 3-5 years, middle childhood; 7-10 years, adolescence; 13-18 years). We then determined how these areas of functioning cluster within developmental domains. Clustering differed between childhood and adolescence. In early and middle childhood, psychological functioning clustered within two related developmental domains: (1) cognition and language and (2) social and emotional functioning. In adolescence, they clustered within three developmental domains (1) cognition and language and (2) social functioning, and (3) emotional functioning. We demonstrate that developmental differences and disorders can be conceptualised as resulting from interactions between different areas psychological functioning. They likely arise through bottom-up processes, whereby difficulties in one area of psychological functioning activate or lead to difficulties in another area. Differences and disorders that appear to be similar, prima facie, may be underpinned by diverse etiologies. Our work provides the basis for network models to inform better identification and support for young people who struggle in school. We expect that our network models will be used as a framework to generate and test hypotheses on the causal pathways between different areas of psychological functioning to developmental differences and disorders.