["Developmental Science, Volume 29, Issue 4, July 2026. ", "\nABSTRACT\n\nChildhood material hardship, including insecurity in housing, utilities, food, and medical care, is a critical factor influencing cognitive functioning and mental health outcomes. However, past research on material hardship is limited by cross‐sectional data and reliance on conventional behavioral measures of cognitive functioning that suffer from poor reliability and lack of specificity. To address these gaps, this study used a well‐validated computational model of cognition to examine individuals’ drift rate, which is hypothesized to be driven by the efficiency of evidence accumulation (EEA) for decision‐relevant information, a key process that supports higher‐order cognitive functioning. Here, we examined how material hardship during childhood was associated with adolescent drift rate, and whether drift rate was linked with attention difficulties. 187 adolescents recruited from the Future of Families and Child Wellbeing Study were included in the analyses. Adolescents exposed to greater material hardship showed lower drift rate, suggesting less effective processing. Growth curve modeling revealed that initial exposure to material hardship, but not changes across childhood, was associated with drift rate in adolescence. Lower drift rate was also associated with concurrent attentional problems and served as a significant indirect pathway linking material hardship to adolescent attention. This is the first longitudinal study that examined the associations among childhood material hardship exposure, adolescent drift rate, and attentional difficulties. Our results suggest that challenges to essential living conditions in childhood may impact cognitive processes underlying goal‐directed behavior in adolescents. These findings highlight the application of computational models to reveal specific cognitive processes impacted by adversity.\n\n\nSummary\n\nExisting research on material hardship and cognitive functioning is limited by reliance on cross‐sectional task‐based performance, resulting in inconsistent findings.\nWe applied the diffusion‐decision model to decompose trial‐wise performance into underlying cognitive processes, including drift rate, a key evidence accumulation process underlying goal‐directed behavior.\nGreater cumulative childhood material hardship, beyond exposure to other adversity, is associated with lower drift rate, which is linked with greater attentional problems in adolescents.\nFindings were specific to drift rate, not average response time or accuracy, emphasizing the value of computational methods in capturing cognitive changes associated with material hardship.\n\n"]