I would define curiosity as a fundamental biological (and human) need. It's what drives the mouses in Tolman's experiments to explore the labyrinth even when sa

I would define curiosity as a fundamental biological (and human) need. It's what drives the mouses in Tolman's experiments to explore the labyrinth even when satiated. It is a need because - from an evolutionary point of view - being curious increases the odds to gain useful knowledge and survive and thrive. Therefore, curiosity, in this perspective, is the intrinsically motivated drive to gain knowledge.