Interest is grounded physiologically/neurologically and has both affective and cognitive components. Research demonstrates that experiencing interest activates the reward circuitry and is therefore rewarding. Educational interventions have begun to demonstrate how individual interest can be used to promote engagement and learning. They also underscore that it is interest in the content that needs to be triggered and sustained, not just superficial connections to the content of one or another task or problem. An educator's style, instructional technology, and organization of materials may all contribute to learners' interest and performance. With the increase of self–other comparisons that accompany the transition to adolescence, peer influence becomes an important factor. The role of group work has been found to contribute to interest development in several studies. Age may be a critical factor in determining to what extent learners need external support to trigger and sustain their interest; however, the learners' phase of interest is also an important consideration. Interested individuals may experience curiosity related to knowledge gaps, and knowledge gaps may lead to the triggering of interest.