The psychology and neuroscience of curiosity

Curiosity is a pervasive yet poorly understood element of human and animal cognition. While it is a primary driver of learning, decision-making, and development, the field has struggled to establish a unified definition. Rather than attempting to force a single definition, this paper advocates for studying curiosity as a broad, internally motivated drive for information. By framing curiosity through the lens of Tinbergen’s Four Questions—function, evolution, mechanism, and development—researchers can better integrate findings across psychology, neuroscience, and ethology.

At its core, curiosity functions to motivate learning by creating a drive state similar to hunger. When an organism perceives a gap in its knowledge, this state motivates the acquisition of information to resolve uncertainty. This process is not limited to humans; simple organisms like C. elegans exhibit sophisticated foraging strategies that maximize both reward and information. In primates, curiosity is often studied using 'bandit tasks,' where subjects must balance the exploitation of known rewards with the exploration of uncertain options. These studies demonstrate that information has intrinsic value, as subjects will often sacrifice tangible rewards to gain knowledge about future outcomes, even when that information provides no strategic advantage.

Neuroscientific evidence suggests that the brain treats information as a reward. Studies using fMRI and single-unit recordings show that curiosity activates canonical reward circuits, including the dopaminergic system and the orbitofrontal cortex. Specifically, dopamine neurons signal a reward prediction error not only for primary rewards like food but also for the acquisition of information. This suggests that the brain integrates informational value into a domain-general reward signal, guiding choices toward informative actions.