Identifying the prevalence, course, and correlates of behavior problems across childhood is of broad interest for researchers, clinical practitioners, parents, and educators. Children displaying disruptive behaviors are at risk for experiencing more conflictual relationships with their teachers and experience the classroom setting as challenging, which can make achieving emotional security difficult for them. Therefore, while positive interactions are important for all children, they may be particularly beneficial for children displaying externalizing behaviors, as well as difficulties in executive functioning (EF), social-emotional development (SED) and behavioral adjustment (BA). In our previous work, child challenging temperament (e.g., high negative reactivity; NR), emotion regulation (ER) difficulties and high-stress reactivity (SR) as well as contextual risk factors (low family-SES and harsh parenting) were implicated in this non-normative developmental pattern [4,8,10,16,18]. Moreover, since appropriate social interaction and adjustment relies on the accurate identification of others’ emotional expressions (as seen in our previous work, 17,18), we wonder if children’s emotion recognition might be one factor underlying their externalizing behavior problems. In support of this hypothesis, recent studies have found links between difficulties in facial emotion recognition (FER) and externalizing behavior in childhood and pre-adolescence [19]. So, more longitudinal studies are required to inform our knowledge of whether FER difficulties are a causal factor in externalizing behaviors. The present study considers how classroom relational environment (classroom-level teacher-child interactions, dyadic teacher-child interactions, and child emotional security) independently and synergistically shape the developmental outcomes (EF, SED, BA) of preschoolers at-risk. We are interested in examining how the quality of dyadic teacher-child interactions and security operate together as a buffering mechanism to regulate children’s classroom behaviors. Moreover, based on evidence indicating that multiple factors may contribute to maladjustment pathways, we will examine the potential role of child (NR, FER, ER, SR) and contextual factors (e.g., family cumulative risk and parent interactive behavior) on the developmental outcomes (EF, SED, BA) of preschoolers at-risk. At last, following the need to identify the protective and risk factors that may alter these trajectories, we will examine the patterns of growth and change in behavior problems across the preschool period in a longitudinal study of children at varying levels of risk for such problems. Our longitudinal design will consist of three data-collection moments (T1, T2 and T3). It starts with a first moment (T1) with 100 children consisting of preschoolers with reported disruptive behaviors paired with a matched control group without the target risk conditions (50 per condition), followed by two subsequent timepoints T2 and T3, approximately 4 months and 8 months after T1, to explore the developmental pathways associated with the proposed risk variables. We will use a multi-informant approach and a multi-method assessment. A composite of classroom relational environment will be created based on three observational measures regarding the quality of classroom-level interactions, quality of dyadic teacher-child interactions, and children’s security. Teacher and child perceptions of their relationship will be evaluated with a teacher’s questionnaire and a child-friendly interview. Several measures will be used to assess children: (i) NR, SED, BA, and ER – teachers’ and parents’ ratings; (ii) EF (cognitive flexibility, working memory, inhibitory control) - three tasks; (iii) global development - developmental assessment battery; (iv) FER – experimental task using facial emotional stimuli; and (v) SR - changes in salivary cortisol during an SR protocol. Children, teachers, and parents’ socio-demographics as well as parent interactive behavior will be evaluated with questionnaires. Contextual risk will also be examined. The longitudinal study of early disruptive behaviors, including several children (NR, FER, ER, SR) and contextual factors (family cumulative risk and parent interactive behavior) is essential to prevent poor outcomes in a child's short-and long-term functioning. Our study will contribute to recognize the developmental catalysts that function as compensatory mechanisms for children at- risk, which is essential to understand resilience in early childhood. Answers to these questions have enormous implications for early intervention/prevention efforts, as well as for understanding of the early emergence of psychopathology.