The Heckman Curve captures the well-known result that the rate of social and economic returns to human capital investments tends to decline as investments occur later in life, suggesting that early childhood investments are the most economically efficient. However, the formal models behind this result assume that the human capital development of one generation is independent of investments in human capital development of other generations. Social science research challenges this assumption by detailing how a child’s human capital development depends on a series of parental conditions — such as job stability, work schedules, time availability and residential location — which are a function of their parent’s human capital. This work-in-progress introduces an agent-based model that extends the mathematical models underlying the Heckman curve to account for the intergenerational dependence of human capital formation. Through empirically informed simulations, this paper shows that under these more realistic foundations, the rate of return to human capital investment is less age-dependent and more evenly distributed across the life course.