How Curiosity Works

To this day, exactly where curiosity originates continues to confound science. Psychologists have gotten a much better handle on classifying aspects of curiosity, though. The big question remains; does it come from within us, or is it a response to our outside world?

One camp in psychology believes that curiosity is an internal drive that originates within us, much like hunger or thirst. This drive theory of curiosity sees curiosity as a naturally-occurring urge that must be satisfied in a very similar manner to how we satisfy our hunger by eating. When our curiosity becomes aroused, we look to new or old interests to satisfy the urge.

The drive theory helps explain curiosity-seeking behavior. It shows us why we actively look for and engage in crossword puzzles or take up a musical instrument. Not only are these activities inherently superfluous, they also contain the risk of failure. Viewed as food for our curiosity, however, they make much more sense.

What drive theory doesn't explain is how object-specific curiosity may be. This is where incongruity theory comes in. This theory is based on the idea that our curiosity is motivated when we're presented with something that doesn't fit into our understanding of the world. We tend to view the universe as predictable and orderly; under incongruity theory, when this order is challenged, our curiosity is aroused. Imagine that while you're reading this article, a pencil on your desk spontaneously moves two inches to the left. This doesn't really fit into our worldview -- pencils aren't supposed to move on their own. Can you imagine not looking around the desk in an attempt to explain why the pencil moved?

In this case, our curiosity was aroused by an external event and we were moved to understand it, which supports incongruity theory.

That said, neither drive theory nor incongruity theory can fully explain curiosity. Each one has trouble fully accounting for one aspect or another, which means that curiosity remains a mystery to us. This doesn't mean we haven't arrived at some real conclusions about it, though. The debate over whether curiosity originates inside us or is a reaction to things we encounter in life has little to do with how the concept is classified.

The idea that curiosity originates inside or outside us has led to two distinct classifications of types of curiosity: state and trait. These two terms describe the way humans engage (or don't engage) in curious behavior. Remember that pencil that moved on its own? The fleeting arousal of curiosity that would evoke curiosity as a reaction is known as state curiosity. It's generally based on an external situation and can be as mundane as wondering what a truck is doing making deliveries at a nearby business at 2:00 a.m. to things as esoteric as considering the afterlife during a funeral.

If all humans are curious by nature, then state curiosity appears to be the best descriptor of this aspect of ourselves. State curiosity tends to be related to high levels of reward, such as excitement [source: Kashdan and Roberts].

The concept that curiosity resides within is known as trait curiosity. This relates to the characteristic of some people to have a lifelong interest in learning, simply for the sake of learning. Throughout its study, trait curiosity has been linked to all manner of behavior, from experimentation with drugs and arson to high intellect and fearlessness. In general, however, it's a positive characteristic.

While studies that attempt to measure trait curiosity often find contradictory evidence to other, similar studies, we can generally look at trait curiosity as a characteristic latent in all of us, but only exhibited in a high order in some of us. To a modern school of psychological thought, trait curiosity is stifled in those who don't display it due to anxiety and fear. Indeed, we risk failure when we venture out to learn new things; we may not master the musical instrument we take up, our efforts to finish a crossword puzzle may be frustrated, or we could end up being injured on a scuba diving trip. You can look at curiosity as the urge that draws us out of our comfort zones and fear as the agent that keeps us within its boundaries [source: Jacobs].

Psychologists further classify trait curiosity based on the variation of interests pursued. Breadth of curiosity is the type where an individual may be interested in a wide array of topics. Depth of curiosity is the level of interest in a single topic. That topic could be anything: dinosaurs, a foreign language, anthropology, astronomy. Any truly deep interest in a specific subject tends to describe depth trait curiosity.

This reveals another big question relating to curiosity: What do we get out of it?

One of the underlying implications of the display of curiosity is that we must derive something from it. As children, we gain an understanding of our world (and that set of predictable expectations that can be disrupted by moving pencils) by constantly interacting with it. We learn things like, red stove: hot, dog's water bowl: wet, hardwood floor: hard. But what real reward is there to learning a great deal about other planets if your day job is in accounting? What's the point of learning another language if you have no plans to travel to its country of origin?

To drive theorists, the answer is that our minds crave distraction. This idea is supported by sensory deprivation studies carried out in the 1950s and 60s. Research has shown that those who are sensorially deprived, kept in rooms without light or sound for extended periods, crave any kind of input. One study investigating the effects of brainwashing found that people will ask to hear very dry information like an old stock report over and over again in the absence of any other kind of stimulation [source: Lowenstein].

We may also get other rewards from curiosity, aside from a means to stave off boredom. Cognitive psychologists propose that we form our identities in part through the information and attitudes we gain from being curious. Under this view, curiosity is like a vehicle we use to expand ourselves. It also appears that curious people are attracted to similarly curious people. One 2004 study found that high levels of trait curiosity tended to predict how close participants felt to one another. Shared levels of trait curiosity beat out even positive trait affect -- having a generally positive outlook on life -- as a factor. So curiosity may serve as a means by which we develop interpersonal relationships, possibly through the lack of fear of failure (in this case, social rejection) associated with curiosity.

On the other hand, a lack of curiosity has been linked to negative emotions. Studies have found that temporarily depressed participants display a lack of state curiosity [source: Rodrigue, et al]. The same holds true for studies of Alzheimer's patients. One 1992 study found that when presented with novel images, Alzheimer's patients spent significantly less time examining them than those without the disease [source: Daffner, et al].

The revelations that curiosity is related to mood uncover yet another question about curiosity: Does it have a biological basis?

Despite having thus far failed to fully explain the existence of curiosity, psychology has contributed much to our understanding. One marker provided by the field, that curiosity is negatively correlated to fear, served as a guide for another scientific discipline, genetics.

In 2007, a team of researchers at the Max Planck Institute discovered what they termed a "curiosity gene" in the great tit songbird. This gene, the Drd4 gene, is responsible for creating receptors for the neurotransmitter dopamine. Birds displaying a common variation on the gene showed a greater propensity to visit new areas and explore unfamiliar objects placed in their cages [source: Max Planck Institute].

Animals have long been known to display their own types of curiosity, like rats exploring new areas of a maze without any expectation of food or reward and primates that learn to open windows on cages to get a peek at what's going on outside in the research lab. While this behavior may not fit the definition of human trait curiosity, the fact that the "curiosity gene" found in great tit birds related to dopamine is significant.

In the human brain, our curiosity is treated much like other pleasurable activities like eating. When we actively pursue new information through our curiosity, we're rewarded with a flood of the pleasure-inducing chemical dopamine.

In addition to the reward system, other areas of the brain play a role in curiosity as well. It appears that regions dedicated to working memory in the prefrontal cortex allow us to distinguish between new and previously experienced stimuli. After all, how could we have anything but curiosity if we couldn't recognize things we've already encountered? It looks like the center most responsible for our sense of curiosity is the dentate gyrus, a part of the brain's hippocampus.

In 2009, researchers discovered that increasing the expression of a protein that interacts with dopamine in the dentate gyrus significantly increased curious behavior in animals [source: PhysOrg]. Again, dopamine appears to play a significant role in curiosity.

Exactly how that role is carried out, and what other aspects of curiosity remains uncovered are still a mystery. Because curiosity is considered the driving force behind scientific curiosity, it's a pretty sure bet that it will eventually lead researchers to a full understanding of itself.