Like other desires and need states that take on an appetitive quality (e.g. food), curiosity is linked with exploratory behavior and experiences of reward. Curiosity can be described as positive emotions and acquiring knowledge; when one's curiosity has been aroused it is considered inherently rewarding and pleasurable. Discovering new information may also be rewarding because it can help reduce undesirable states of uncertainty rather than stimulating interest. Theories have arisen in attempts to further understand this need to rectify states of uncertainty and the desire to participate in pleasurable experiences of exploratory behaviors.

Curiosity-drive theory

Curiosity-drive theory relates to the undesirable experiences of "uncertainty". The reduction of these unpleasant feelings, in turn, is rewarding. This theory suggests that people desire coherence and understanding in their thought processes. When this coherence is disrupted by something that is unfamiliar, uncertain, or ambiguous, it is curiosity-drive that attempts to gather information and knowledge of the unfamiliar to restore coherent thought processes. Through this theory, the general concept dictates that curiosity is developed strictly out of the desire to make sense of unfamiliar aspects of one's environment through interaction of exploratory behaviors. Once understanding of the unfamiliar has been achieved and coherence has been restored, these behaviors and desires will subside.

Subsets of curiosity-drive theory differ on whether curiosity is a primary or secondary drive and if this curiosity-drive is originated due to one's need to make sense of and regulate their environment or if it is caused by an external stimulus.[7] Causes can range from basic needs that need to be satisfied (e.g. hunger, thirst) to needs in fear induced situations.[7] Each of these subset theories state that whether the need is primary or secondary curiosity is developed from experiences that create a sensation of uncertainty or perceived unpleasantness. Curiosity then acts as a means in which to dispel this uncertainty. By exhibiting curious and exploratory behavior, one is able to gain knowledge of the unfamiliar and thus reduce the state of uncertainty or unpleasantness. This theory, however, does not address the idea that curiosity can often be displayed even in the absence of new or unfamiliar situations.[8] This type of exploratory behavior is common in many species. Take the example of a human toddler who, if bored in his current situation devoid of arousing stimuli, will walk about until something interesting is found. The observation of curiosity even in the absence of novel stimuli pinpoints one of the major shortcomings in the curiosity-drive model.

Optimal-arousal theory

Optimal-arousal theory developed out of the need to explain the desire for some to seek out opportunities to engage in exploratory behaviors without the presence of uncertain or ambiguous situations. Optimal-arousal theory attempts to explain this aspect of curiosity by suggesting that one can be motivated to maintain a pleasurable sense of arousal through these exploratory behaviors.

The concept of optimal-arousal of curiosity suggests that the desire is to maintain an optimal level of arousal. If the stimulus is too intensely arousing, a "back-away" type behavior is engaged. In contrast, if the environment is boring and lacks excitement, exploratory behavior will be engaged until something optimally arousing is encountered. In essence, there is an intrinsic motivation to search for a perfect balance of arousal states.[8] This idea attempts to address the observed behaviors of curiosity even in the absence of uncertain or unfamiliar situations. While optimal-arousal theory addresses some discrepancies within curiosity-drive theory, there seems to be a distinctive counter-intuitiveness about their designs. For example, if there is an ideal state of curiosity that should be maintained, then gaining new knowledge to eliminate that state of curiosity would be counter-productive.[7][8]

Integration of the reward pathway into theory

Taking into account the shortcomings of both curiosity-drive and optimal-arousal theories, attempts have been made to integrate neurobiological aspects of reward, wanting, and pleasure into a more comprehensive theory for curiosity. Research suggests that the act of wanting and desiring new information directly involves mesolimbic pathways of the brain that directly account for dopamine activation. The use of these pathways and dopamine activation may account for the assigning of value to new information and then interpreting as reward.[7][9][10] This aspect of neurobiology can accompany curiosity-drive theory in motivating exploratory behavior.