Social-emotional development has been widely recognized as an important component of early childhood education, and includes children’s experience, expression, and regulation of emotions, as well as abilities to establish and maintain positive relationships with others. These social-emotional competencies contribute to children’s school readiness, allowing children to enter school prepared to engage and learn with peers and teachers. According to a bioecological perspective, children’s interactions with their environments impact their development. Thus, in considering healthy environments that promote social-emotional development, this entry highlights the roles of children’s temperaments and environments such as the home and family, child care and schools, and communities and cultures.