Performance-based measures of children's executive functions (EFs) do not capture children's application of these skills during everyday emotionally-laden and socially-mediated interactions. The current study demonstrates the value of using assessor report of self-regulation behaviors (inhibitory control and positive affect/engagement) in addition to EF tasks when studying early childhood experiences and development in a rural lower-middle-income country setting. In a sample of 1302 disadvantaged 4-year-olds living in rural Pakistan, we found that directly assessed EFs were significantly related to assessor observations of children's inhibitory control and positive affect/engagement during a structured assessment protocol. However, EFs and two types of self-regulation behaviors demonstrated unique associations with children's (1) "contextual experiences," as indexed by family socio-economic resources, participation in parenting interventions, and children's physical growth; and (2) "age-salient developmental outcomes," as indexed by direct assessment of pre-academic skills and maternal report of prosocial behaviors and behavior problems. First, family wealth uniquely predicted only observed positive affect/engagement, whereas maternal education uniquely predicted only EFs. Second, children's antecedent linear growth was a significant predictor of both EFs and positive affect/engagement, but exposure to an enhanced nutrition intervention during the first 2 years of life and preschoolers' hair cortisol concentration were associated only with observed self-regulation behaviors. Finally, both EFs and observed positive affect/engagement uniquely predicted children's pre-academic skills. In contrast, only assessors' ratings of positive affect/engagement uniquely predicted maternal report of prosocial behaviors and only assessors' ratings of inhibitory control uniquely predicted maternal report of behavioral problems.