Subgroups of temperament associated with social–emotional difficulties in infants with early signs of autism

<p dir="ltr">Links between temperament and social–emotional difficulties are well-established in normative child development but remain poorly characterized in autism. We sought to characterize distinct temperament subgroups and their associations with concurrent internalizing and externalizing symptoms in a sample of 103 infants (Mage = 12.39 months, SD = 1.97; 68% male) showing early signs of autism. </p><p dir="ltr">Latent profile analysis was used to identify subgroups of infants with distinct temperament trait configurations on the Infant Behavior Questionnaire-Revised. Derived subgroups were then compared in terms of internalizing and externalizing symptoms on the Infant–Toddler Social and Emotional Assessment. </p><p dir="ltr">Three distinct temperament subgroups were identified: (a) inhibited/low positive (n = 22), characterized by low Smiling and Laughter, low High-Intensity Pleasure, low Vocal Reactivity, and low Approach; (b) active/negative reactive (n = 23), characterized by high Activity Level, high Distress to Limitations, high Sadness, high Fear, and low Falling Reactivity; and (c) well-regulated (n = 51), characterized by high Cuddliness, high Soothability, and high Low-Intensity Pleasure. There were no differences in infant sex ratio, mean age or developmental/cognitive ability. Inhibited/low-positive infants had significantly more behavioral autism signs than active/negative reactive and well-regulated infants, who did not differ. Inhibited/low-positive and active/negative reactive infants had higher internalizing symptoms, relative to well-regulated infants, and active/negative reactive infants also had higher externalizing symptoms. These findings align closely with those garnered in the context of normative child development and point to child temperament as a putative target for internalizing and externalizing interventions. </p>