PROJECT SUMMARY Extant research on paternal caregiving in early childhood has typically relied on traditional caregiving dimensions derived from research and theory on mothers (e.g., sensitivity).2 However, some have argued that fathers play a unique role in promoting children's experiences and relationships with individuals outside of the security provided by attachment relationships through activation parenting (AP).5,13,14 AP includes behaviors that challenge children to approach novel situations, explore their environments, and take physical and socioemotional risks, through a balance of encouragement and limit-setting.3,4,7,15 Whereas components of AP have been linked to children's self-regulation (SR) skills, comprehensive measures of AP and, importantly, longitudinal research on Black and Latinx families from low socioeconomic backgrounds is lacking.7 These limitations greatly constrain our understanding of the potential benefits of paternal AP for children's emerging SR. Thus, the overall goal of the application is to test associations between paternal AP, paternal characteristics, and children's SR skills, in a sample of low-income, ethnically-diverse fathers. The specific aims are to: 1) validate a novel AP coding scheme and generate a latent factor for paternal AP in clean-up and teaching tasks; 2) test unique associations between paternal AP and children's SR skills, with the hypothesis that higher levels of paternal AP will be associated with higher child SR at ages 4 and 5, especially for children who exhibit an optimal level of activation; and 3) test unique associations between paternal factors and paternal AP, with the hypothesis that higher family income and paternal education, lower paternal depressive symptoms, and being Black and/or Latinx will be associated with higher levels of paternal AP. The 24-month training plan proposed in the application will provide necessary training to support the applicant in advancing their expertise to become an independent researcher. The program of training comprises three areas: 1) expand knowledge of research on fatherhood, especially Black and Latinx fathers; 2) gain experience with methods used in observational coding of parent-child interactions with a specific focus on the construct and coding of AP; and 3) learn and apply multilevel analytic procedures to multivariate analyses. Professional development opportunities will be infused throughout the training period. Results from the proposed research could have important implications for basic and applied research on children's SR, and specifically promoting AP in fathers during early childhood. Similarly, improving understanding of the determinants of paternal AP would also inform future targets of prevention efforts to promote paternal AP in early childhood.