Research suggests that 18- but not 14-month-olds understand that preferences are diverse. We investigated what transitions occur between 14- and 18 months to allow older infants to understand that preferences are subjective and whether younger infants can be trained to learn about the diversity of preferences. Infants under 18 months of age in two different training conditions were either shown that two experimenters liked the same objects as each other or different objects. Following training, all infants were asked to share food with the experimenter. When infants were trained with two experimenters liking different objects, they later provided the experimenter with the food she liked; however, when infants were trained with two experimenters liking the same objects, they shared the food that they themselves liked. Our results suggest that training allows infants to overturn an initial theory in the domain of Theory of Mind for a more advanced one.