McCatharn, Jennifer MarieInterest in improving children’s executive function (EF) skills through interventions is increasing and several approaches have been tested (Takacs & Kassai, 2019). However, there is a need to further focus on specific populations of students, such as young students. The focus on young children (under age 7) in the synthesis and in the subsequent intervention studies is important as there is evidence that EF development has specific theoretical and empirical groundings to consider for this age group. Chapter 2 of this dissertation is a synthesis of mindfulness-based interventions targeting the EF skills of young children. The synthesis examines nine studies and provides in-depth descriptions of the interventions, ratings of the methodological rigor, and reports the effects of interventions. Chapter 3 reports the findings from a randomized control trial of two intervention approaches: mindfulness and social-emotional learning (SEL) conducted in small groups. Chapter 4 describes a second study which explores the effects of implementing a novel intervention (Mindfulness + SEL) to whole classrooms of students in kindergarten compared to a historical control group from the first study. Although the outcomes of most omnibus tests performed were non-significant in both studies, inspection of the effect sizes seemed to demonstrate a pattern of EF skill improvement favoring students in the intervention conditions over control group students. Both studies occurred in a public school in a typically under-resourced community, thus the findings are likely be relevant to schools with similar demographic profiles. This dissertation contributes to the field in the following ways: the synthesis provides a specific focus on EF skill development and interventions for children under age 7, Study 1 provides a comparison of two EF intervention approaches which have not been directly compared, and Study 2 provides preliminary data on the implementation of a combined, practitioner informed intervention. Both studies utilize an EF measure which has strong psychometric properties and matches the age appropriate construct of EF. The effects reported in both studies will likely contribute to future meta-analyses of EF interventions, as well as to the planning of future interventions. Areas for future research are discussed throughout the dissertation.enDissertationEducationPsychologyCurriculum development