Abstract

Despite growing interest in attachment research within neurodivergent populations, limited attention has been paid to how attachment is assessed in these groups. Addressing this gap, the present study examines the factorial structure and measurement invariance of the Spanish brief version of the Experiences in Close Relationships Scale (SB-ECR-12) in neurotypical and neurodivergent (autistic and/or with attention deficit) emerging adults. The sample consisted of 443 Chilean emerging adults (60.9% female) aged 18–29 years, including 169 neurodivergent and 274 neurotypical individuals. Confirmatory factor analysis revealed good fit to a two-factor model and supported measurement invariance (configural, metric, scalar, strict) of the SB-ECR-12 across neurodivergent and neurotypical. However, latent mean comparisons indicated significant group differences: neurodivergent individuals reported higher levels of both attachment anxiety and avoidance. These findings provide evidence of the SB-ECR-12’s validity and reliability (attachment anxiety and avoidance: ? and ? > .85) for assessing attachment insecurity in neurodivergent populations. © 2025 Society for the Study of Emerging Adulthood and SAGE Publishing