The possibility, which is based on the concept of reactive personality-environment transactions, that individuals learn different things from the same experience as a function of personality differences may help explain individual differences in adult developmental trajectories. In an analogue, longitudinal design, business students were taught about stock market investing, and they engaged in 5 practice investment sessions. Although all participants earned the same returns on their investments, they varied in the expectancies they formed about stock investing as a function of their personality status. As anticipated, behavioral inhibition (heightened sensitivity to punishment) facilitated formation of negative investing expectancies and antagonized formation of positive investing expectancies, and behavioral activation (heightened sensitivity to reward) facilitated formation of positive investing expectancies and antagonized formation of negative investing expectancies. Differential learning in a task that approximated skill acquisition for a developmental transition implies that personality may help shape individual developmental trajectories in the adult years.