Continuity of temperament subgroup classifications from infancy to toddlerhood in the context of early autism traits.

Researchers followed 103 babies showing early signs of autism from 12 to 24 months old. They found that babies could be grouped by temperament (personality traits) into different types, and most children stayed in the same group over time. These temperament groups were linked to social skills and autism traits. This suggests that understanding a baby's temperament early on might help predict their autism characteristics and social development.

This longitudinal study followed 103 infants (68% male) showing early autism traits from 12 to 24 months, examining the stability of temperament-based subgroups over time. Using latent profile analysis, researchers identified consistent temperament subgroups: inhibited/low positive, active/negative reactive, and sociable/well-regulated at all timepoints, with an additional reactive/regulated subgroup emerging at 24 months. Children showed significant likelihood of maintaining their temperament classification across assessments. These temperament subgroups were associated with concurrent social-emotional functioning and autism traits, but were unrelated to age, sex, or developmental level.

The findings suggest temperament subgroups may serve as early, reliable indicators of autism characteristics and social-emotional functioning in very young children.

Temperament assessment in infancy may provide early indicators of autism characteristics and social-emotional functioning. This could inform early intervention planning and help professionals understand individual differences in autism presentation from a very young age.

Sample limited to infants already showing autism traits, potentially limiting generalizability. No comparison with typically developing children. Movement patterns between subgroups were unclear when changes occurred, suggesting some classification instability.

Our previous cross-sectional investigation (Chetcuti et al., 2020) showed that infants with autism traits could be divided into distinct subgroups based on temperament. This longitudinal study builds on this existing work by exploring the continuity of temperament subgroup classifications and their associations with behavioral/clinical phenotypic features from infancy to toddlerhood. 103 infants (68% male) showing early signs of autism were referred to the study by community healthcare professionals and seen for assessments when aged around 12-months (Time 1), 18-months (Time 2), and 24-months (Time 3). Latent profile analysis revealed inhibited/low positive, active/negative reactive, and sociable/well-regulated subgroups at each timepoint, and a unique reactive/regulated subgroup at Time 3. Cross-tabulations indicated a significant likelihood of children having a recurrent subgroup classification from one timepoint to the next, and no apparent patterns to the movement of children who did change from one subgroup to another over time.

Temperament subgroups were associated with concurrent child social-emotional functioning and autism traits, but unrelated to child age, sex, or developmental level. These findings suggest that temperament subgroup classifications might represent a reliable and very early indicator of autism characteristics and social-emotional functioning among infants/toddlers with autism traits.