“…Specifically, teachers who are sensitive and responsive to children's emotional and social needs and who create a positive classroom climate are hypothesized to contribute to children's sense of security (Downer, Sabol, & Hamre, 2010) and thereby support children in establishing and maintaining positive relationships with teachers and peers and developing behavior regulation (Merritt, Wanless, RimmKaufman, & Peugh, 2012;Rimm-Kaufman, Curby, Grimm, Nathanson, & Brock, 2009). This assumption is confirmed in real-world observational studies (e.g., Burchinal, Kainz, & Cai, 2014;Mashburn et al, 2008;NICHD ECCRN, 2006;Sylva, Melhuish, Sammons, Siraj-Blatchford, & Taggart, 2011) and in experimental studies showing that social-emotional curricula and professional development tools focusing on teachers' responsive interactions can enhance children's social skills, behavior regulation, and emotion understanding (Bierman et al, 2014;Landry et al, 2014). However, the associations in these observational and experimental studies tend to be small, and often there are null findings for some of the assessed outcome measures.…”