What’s the evolved function of curiosity?

Image courtesy of Jeffrey Pang via Wikimedia Commons

Neuron “The Psychology and Neuroscience of Curiosity” (Kidd & Hayden 2015)

This is a fantastic review of what is known about curiosity and what needs to be learned about curiosity in the near future. I was glad to see the “four questions” approach to curiosity here. Tinbergen’s questions frequently prove to be the framework that dramatically reduces confusion about behavior, and here looking at curiosity through these four lenses allows for better overall understanding of the behavior. Although it is funny how psychologists — whose work is inherently on proximate causes — swap the order of the Tinbergen questions… to me the ultimate questions of “function” and then “evolution” are best placed last (this is a matter of taste I suppose).

It seems like two different paradigms of curiosity need to be reconciled, one that sees curiosity as meeting a need for information (analogous to responding to hunger) and one that sees curiosity as a value-added endeavor seeking novel information-for-information’s-sake (analogous to forms of play). My instinct is that curiosity is most often parallel to play in being defined as not for “immediate strategic reasons”. Curiosity is a kind of cognitive play, and contrasts with the use of cognitive skills to directly obtain rewards or other resources.

I was fascinated by what some of the tests of curiosity tell us about the behavior. Odd “4-arm restless bandit” tests reveal the “what if” nature of curiosity, showing that it is valuable to test out new options if you live in a stochastic and variable environment. Monkey studies suggest that the information obtained via curiosity is valuable, because experimentally animals are willing to pay a cost in order to have their curiosity sated. And what makes us curious — both as children and adults — is interesting. We gravitate to intermediate information states — not too novel, not too familiar — in our curiosity. Things that make us curious are “optimally discrepant”, which could put us into a zone of proximal development that’s ideal for learning. We are also inherently scientific in our curiosity, looking to deconfound variables and test hypotheses, suggesting that scientists just happen to be curious for a living.

I am not that knowledgable about neuroscience, so sometimes studies reporting the lighting up of brain anatomy during different mind-states leads my eyes to glaze over. But this review makes it clear how valuable it is to know the neural mechanisms of curiosity: parallels to other known mind-states associated with the same neural mechanisms (anticipation of rewards, learning after having novel information revealed) allow us to better understand the potential function of curiosity.

There’s great perspective on animal curiosity continuums in this review. If curiosity is about information-seeking, then there’s no reason to categorically privilege more complex forms of information seeking such as those displayed by humans. It’s really feasible that human curiosity is not a novel development, but a refinement of traits first evolved in very basal animal common ancestors.

Interestingly it seems like the least is known about curiosity from the perspective of its evolution, with function implying benefits that would lead to a fitness advantage to more curious individuals but no studies really measuring actual benefits associated with curiosity. All behavioral adaptations are hard to look at from the evolutionary perspective, but as this article suggests there is the opportunity to use a comparative approach to understand the continuity of curiosity across animal taxa.

I agree with these authors’ suggestion to let definitions emerge from data rather than using a priori definitions before we know enough about a behavior. It is a common mistake for scientists to try to create taxonomies before we actually know what characteristics create meaningful categories. In this case there is a danger of over-classifying forms of curiosity before a we have a broad survey of the nature of the behavior.

Even though what we know about curiosity is pretty meager, there are some interesting applications that can be made from what is known. This review made me think about how gambling as an industry might exploit human curiosity; if that is the case, there’s a rationale for laws that limit what the gambling industry can offer to its inherently-curious and therefore inherently-exploitable clientele. I also was struck by how what we know about curiosity might be applied in the classroom. Maximizing curiosity in the classroom could maximize learning, so we need to find that zone of proximal development, which also corresponds with where students should be the most curious. This article provides a great rationale for letting students lead their own inquiries in classwork and on class projects.