The development of autistic social traits across childhood and adolescence in males and females

Background Autism is a dimensional condition, representing the extreme end of a continuum of social competence that extends throughout the general population. Currently, little is known about how autistic social traits ( AST s), measured across the full spectrum of severity, develop during childhood and adolescence, including whether there are developmental differences between boys and girls. Therefore, we sought to chart the trajectories of AST s in the general population across childhood and adolescence, with a focus on gender differences. Methods Participants were 9,744 males ( n = 4,784) and females ( n = 4,960) from ALSPAC , a UK birth cohort study. AST s were assessed when participants were aged 7, 10, 13 and 16 years, using the parent‐report Social Communication Disorders Checklist. Data were modelled using latent growth curve analysis. Results Developmental trajectories of males and females were nonlinear, showing a decline from 7 to 10 years, followed by an increase between 10 and 16 years. At 7 years, males had higher levels of AST s than females (mean raw score difference = 0.88, 95% CI .72, 1.04), and were more likely (odds ratio OR = 1.99; 95% CI , 1.82, 2.16) to score in the clinical range on the SCDC . By 16 years this gender difference had disappeared: males and females had, on average, similar levels of AST s (mean difference = 0.00, 95% CI −0.19, 0.19) and were equally likely to score in the SCDC 's clinical range ( OR = 0.91, 95% CI , 0.73, 1.10). This was the result of an increase in females’ AST s between 10 and 16 years. Conclusions There are gender‐specific trajectories of autistic social impairment, with females more likely than males to experience an escalation of AST s during early‐ and midadolescence. It remains to be discovered whether the observed female adolescent increase in AST s represents the genuine late onset of social difficulties or earlier, subtle, pre‐existing difficulties becoming more obvious.