Abstract
This longitudinal study focused on early behavioural problems and autistic traits. In a stratified, population-derived sample of 119 children, mothers reported through questionnaires on externalizing, internalizing, and social-communicative characteristics of their child in infancy (14 months) and toddlerhood (37 months), and on autistic traits at preschool age (4-5 years). Children with consistently normal behaviour from infancy to toddlerhood showed lower autistic traits at preschool age than children with deviant behaviour on one or both time points. High autistic traits at preschool age were predominantly preceded by problems in interaction, communication, language, play, and affect in infancy and/or toddlerhood, but also by inattention in toddlerhood. Adequate support and specific interventions in these domains are needed in an attempt to diminish further derailment of the child's behaviour and development, and to prevent the full manifestation of ASD or related disorders such as ADHD.
