Cortisol, a hormone associated with the stress response, affects adult performance on learning and memory tasks, yet whether cortisol helps or hinders performance depends on the direction of cortisol change during the task, the amount of change, and the type of task. Past studies of infants are few and confl icting regarding whether an increasing or decreasing cortisol reactivity pattern facilitates cognitive performance. Similarly, few studies have assessed whether an association exists between maternal sensitivity and learning in infancy. The present study assessed relations between...