Background <p>Caregivers’ skillsets and allocation of resources, time, and attention can affect child development. Cash transfer (CT) programs directly increase household resources and can improve child development.</p> Objective <p>This study investigated how a CT changes the relationship between caregiver cognitive skills and child cognitive development, hypothesizing the CT improves cognitive development more for children of caregivers with lower logical reasoning scores.</p> Method <p>This analysis used cluster-randomized trial data from children (<i>N</i> = 2,153, ages 3–7, 49% female) and their caregivers (<i>N</i> = 1,392, average age 30.5 years, 99% female) participating in the Zambia Child Grant Program impact evaluation. Adult logical reasoning was measured through a short set of Raven’s Progressive Matrices. Child cognition was measured via caregiver report. Scores for both adults and children were estimated using item response theory. Linear and nonparametric regression analyses were conducted to identify CT impact heterogeneity on early child cognitive development across the spectrum of adult logical reasoning scores.</p> Results <p>Multiple statistical approaches indicate the CT improved cognitive development more for children of caregivers with lower logical reasoning scores. The CT increased cognitive scores more for children of caregivers with logical reasoning scores in the low (0.34 standard deviations [SD], <i>p</i> &lt; 0.001) and middle terciles (0.24 SD, <i>p</i> &lt; 0.01) compared to children whose caregivers had logical reasoning scores in the high tercile. These heterogeneous impacts were concentrated among children not attending school.</p> Conclusions <p>This analysis concluded the CT had a homogenizing effect on child cognitive development in the absence of education.</p>