In the past decades, an increasing number of Dutch parents made use of early non-parental child care (ENPCC), where babies and young children are systematically cared for by caregivers other than their parents (NJI, 2022). In what way ENPCC impacts the social-emotional development of children is the topic of an ongoing societal and scientific debate (Arace et al., 2021). Social-emotional development (SED) comprises social competence as well as (the absence of) internalizing and externalizing problems (Linberg et al., 2020). Currently, research findings on the effects of ENPCC on SED are divergent: Some studies report a positive effect (Lekhal, 2012; Stolk et al., 2013) or fail to find a link (Love et al, 2003). However, most studies found that ENPCC is negatively related to SED (Albers et al., 2016; Averdijk, Ribeaud, & Eisner, 2022; Van Beijsterveldt, Hudziak, & Boomsma, 2005; Beijers et al., 2013; NICHD, 2003). As studies vary in what aspects of ENPCC are considered, research that includes multiple ...