Why are humans so curious?

Humans are innately curious creatures. But have you ever wondered why?

Astrophysicist Mario Livio has. And now, he explores this question in a new book, "Why? What Makes Us Curious."

“I chose this particular word, ‘why,’ because this particular question is uniquely human,” Livio says. “Other animals are curious, but only humans are worried and curious about reasons and causes for things. Only humans really ask the question, ‘Why?’”

Is curiosity something that we are born with? Definitely, Livio says.

“There are many studies that have shown that there is a strong genetic component to curiosity,” he notes. “It is also the case that some people are more curious than others, in the same way that some people have talent for music and others don’t or some people are smarter than others … But all people are curious, with the possible exception of people who are very deeply depressed or have certain kinds of brain damage.”

Humans exhibit two basic types of curiosity that show up in different parts of the brain during functional MRI scans.

One type has been dubbed "perceptual curiosity," Livio says. This is what we feel when we see something that surprises or puzzles us or doesn’t match up with something we thought we knew. “It is felt as a sort of uneasiness, an unpleasant situation, a bit like an itch you need to scratch,” he explains.

A second kind has been dubbed "epistemic curiosity." This is our love of knowledge, our desire to learn new things. “Our brain and our mind assigns value to this knowledge, so this is usually experienced as a pleasurable thing, with an anticipation of reward in the form of what we learn,” Livio says.

Kids are born scientists, Livio says. “Small children really want to understand cause and effect very early on. They somehow grasp that every effect is related to some cause and they want to understand those relations because that helps them to cope with their environment and to make fewer errors in their everyday lives.”

So, why does curiosity tend to diminish as we grow up?

“When we grow up, it’s not that we are not curious anymore, but our curiosity changes somewhat from the type that I call perceptual — which is being interested in many things and [having the ] willingness to even take risks for novelty — towards the epistemic curiosity, the love of knowledge,” Livio explains. “The love of knowledge stays with us throughout every time, all ages. Even when you are very old, people still are what somebody called ‘infovores’ — they want to devour information. [But] that willingness to take risks for novelty is definitely declining.”

Curiosity — in case you were wondering — has an evolutionary purpose: People had to be curious about what was happening around them or they wouldn’t survive. “People had to know, for example, what happens when you walk off a cliff because if you do that too often, it’s not going to have a good ending.”

“[But] the interesting thing, and one of the things that researchers still don’t have an answer to, is that we, as humans, seem to be much more curious than what is just necessary for survival,” Livio points out. Curiosity can also function as a coping mechanism. “Curiosity is the best remedy for fear,” he writes in his book.

“Very often we are afraid of things we don’t know much about or we don’t understand, and if we become curious about them and learn more about them, then we are much less afraid,” he explains.

In the age of Google, humans can satisfy one additional type of curiosity more easily than ever before: "specific curiosity." This is when you need a particular piece of information, like the author of a book, for example.

The internet is, of course, fantastic for this and relieves us of that specific type of curiosity quickly, Livio says. Scientific research or big artistic projects, however, generally deal with questions for which humanity has not yet found an answer.

“Technology has allowed us to get rid of those immediate specific curiosity types of things, but it still allows us to continue to be epistemically very, very curious,” Livio says. “The only reason I ended up doing all this research on curiosity and writing this book is because I became extremely curious about curiosity and how it works.”

This article is based on an interview that aired on PRI’s Science Friday with Ira Flatow.