The purpose of this project is to explore if childhood stress impacts memory, sleep quality, and brain development in preschool children and if this relationship is moderated by their parents’ experiences of early life stress. Previous research suggests mothers’ childhood history has a direct impact on their emotional stress while parenting, and this emotional stress had a direct impact on their child's behavior. Other research has shown that early life stress experienced by children can negatively impact various aspects of children's development including memory, sleep quality, and neural connectivity. However, there is little research investigating how parents’ experiences of childhood stress may further impact child development. All data will be taken from an ongoing longitudinal study investigating memory, sleep, and brain development in preschoolers, including: early life parental stress (Questionnaire of Unpredictability in Childhood; QUIC), childhood stress (Chaos, Hubbub, and Order Scale; CHAOS), and memory via the Lure Discrimination Index from the Mnemonic Similarity Task. Sleep quality will be measured using the number of arousals during overnight polysomnography and brain development will be assessed using total volume (white and grey). We hypothesize that increased childhood stress will negatively predict memory, sleep quality, and brain volume of preschool children. Additionally, we hypothesize that higher childhood stress experienced by parents will further negatively predict all three variables. Results may further explain how early childhood experiences can impact their children’s development.