Developmental trajectories of autistic social traits in the general population.

Researchers followed nearly 10,000 children from age 7 to 16, tracking autism-like social traits over time. They found four patterns: most children (83%) had consistently low traits, while smaller groups showed consistently high traits (2%), increasing difficulties (7%), or improving skills (7%). Girls were more likely to develop social difficulties during teenage years alongside mood and behavior problems, while boys were more likely to show improvement. This shows that autism-like traits can change significantly during childhood and adolescence.

This longitudinal study examined autism trait trajectories in 9,744 children from the general population, measured at ages 7, 10, 13, and 16 using the Social and Communication Disorders Checklist. Growth Mixture Modelling identified four distinct trajectory groups: Persistent High (2.3%), Persistent Low (83.5%), Increasing (7.3%), and Decreasing (6.9%). The Increasing group, predominantly female (53.2%), showed dramatic rises in autism-like social traits during adolescence alongside escalating mental health difficulties. The Decreasing group was majority male (63.6%) and demonstrated improving social skills over adolescence.

These findings highlight the dynamic nature of autism traits across development and suggest important sex differences in trajectory patterns.

Clinicians should monitor for emerging autism-like social difficulties during adolescence, particularly in females presenting with concurrent mental health concerns. Recognition that autism traits can change over time supports dynamic assessment approaches rather than static diagnostic assumptions. Males may show natural improvement in social skills during adolescence.

Study type not specified in metadata. Relies on checklist measures rather than clinical diagnosis. General population sample may not fully represent clinical autism presentations. Trajectory groups were relatively small, limiting generalizability of findings.

Autistic people show diverse trajectories of autistic traits over time, a phenomenon labelled 'chronogeneity'. For example, some show a decrease in symptoms, whilst others experience an intensification of difficulties. Autism spectrum disorder (ASD) is a dimensional condition, representing one end of a trait continuum that extends throughout the population. To date, no studies have investigated chronogeneity across the full range of autistic traits.

We investigated the nature and clinical significance of autism trait chronogeneity in a large, general population sample. Autistic social/communication traits (ASTs) were measured in the Avon Longitudinal Study of Parents and Children using the Social and Communication Disorders Checklist (SCDC) at ages 7, 10, 13 and 16 (= 9744). We used Growth Mixture Modelling (GMM) to identify groups defined by their AST trajectories. Measures of ASD diagnosis, sex, IQ and mental health (internalising and externalising) were used to investigate external validity of the derived trajectory groups.

The selected GMM model identified four AST trajectory groups: (i) Persistent High (2.3% of sample), (ii) Persistent Low (83.5%), (iii) Increasing (7.3%) and (iv) Decreasing (6.9%) trajectories. The Increasing group, in which females were a slight majority (53.2%), showed dramatic increases in SCDC scores during adolescence, accompanied by escalating internalising and externalising difficulties. Two-thirds (63.6%) of the Decreasing group were male. Clinicians should note that for some young people autism-trait-like social difficulties first emerge during adolescence accompanied by problems with mood, anxiety, conduct and attention.

A converse, majority-male group shows decreasing social difficulties during adolescence.