Human cognitive architecture has evolved throughout history, thus facilitating the processing of certain types of knowledge that emerged early on in evolution and that have an adaptive benefit (e.g., recognizing faces or food). Despite its complexity, primary knowledge is processed almost effortlessly, as opposed to secondary knowledge which developed later during the course of evolution and which requires extra cognitive resources and motivation for processing (e.g., "academic" knowledge, such as mathematics or grammar). Primary knowledge also constitutes the basis for secondary knowledge. Using primary knowledge to encourage individuals to invest in a task that is not motivating has therefore been used in recent studies as a promising avenue of research. This study presents 3 experiments in which university students had to complete statistics exercisesstatistics being renowned as a difficult discipline typically disliked by students. The task presented problem-solving exercises which were identical in structure but which differed in content, by referring to either primary or secondary types of knowledge. Primary knowledge content, particularly when presented first, enhanced performance and efficiency while maintaining motivation during problem solving. Participants appeared to be unaware of this positive effect. By contrast, secondary knowledge content had a negative effect on performance and seemed to reduce motivation when presented first. These findings suggest that the use of easy-to-process primary knowledge can enhance learningsimply by manipulating task content and presentation order.