Babies are smart. For centuries, dating at least as far back as the Greek philosophers Plato and Aristotle, people have wondered about the origins of knowledge. Where does it come from? Are humans born with knowledge? Or do they acquire it through the experiences they have interacting with the world?
Although there have been countless attempts at answering this question, modern day psychologists are still arguing about the relative contributions of nature and nurture. Some might claim that we aren't any closer to an answer than we were 2000 years ago. I beg to differ. Over the centuries, scientists have gained an understanding of the physical world, including the people that inhabit it, that is beginning to shed some light on this fundamental question.
The brilliant philosopher and the "father of psychology", William James, offered his famous view in 1890 in his book, The Principles of Psychology. He described the mental experience of the newborn infant as a, "blooming, buzzing, confusion," meaning that at first, infants do not experience the world like adults (or even children) do, populated with distinguishable objects and surfaces that possess features such as size, color, shape, and meaning. In other words, when your brand new baby looks around your living room, they don't see the couch, a coffee table, a rug, or the dog -- they don't even see you as a "thing" with any meaning.
Fortunately for parents, the story told by developmental psychologists today is a very different one. What researchers have shown, is that even though babies (obviously) have to learn an enormous amount of information about the world (how could they possibly be born knowing about microwaves and iPods), they do seem to be born with some very basic, fundamental knowledge that gives them a head start on making sense of things.
In a few domains, babies seem to have intuitions that guide their expectations about how important entities in the world (e.g., objects, people) act and interact. For example, babies appear to be born knowing that objects cannot magically appear or disappear, that they cannot pass through each other, and that they cannot move unless contacted by another object. These expectations hold for objects, but not for non-object entities like substances (e.g., liquid, sand).
Babies also are born amateur psychologists. They begin life preferring to look at faces over other things in their environment, and they possess a sophisticated understanding of the minds of others (e.g., that their own knowledge can differ from another individual's, that a person's behavior is directly related to their knowledge, that a person's actions are dependent upon the goals they have). Clearly, such knowledge is adaptive. And, rather than taking a chance on infants learning (or not learning) things as important as how objects and people behave, evolution has instead built this information into our brains.
Another domain, one that is the focus of my own research, is number knowledge. If someone would have told me 15 years ago (and they did!) that babies are born with the ability to count, I would have been (and was) reluctant to believe it. How could babies, who at first can't do much of anything besides breathe, eat, and cry, have an understanding of something as abstract and ethereal as number?
Until very recently, psychologists (and philosophers, linguists, and anthropologists, among others) believed that it is impossible to have a concept of number without first having language. That is, numbers are so abstract, that they can't possibly be conceived unless you have some abstract code (i.e., language) in which to express them. This leads to the inevitable conclusion that babies don't have the means for conceptualizing number.
Despite this, the last few decades have seen an explosion of research showing that even newborn babies are sensitive to number. In fact, by their first birthday (and long before they can talk), babies exhibit quite sophisticated number knowledge. They can enumerate visual and auditory items, items presented sequentially and items presented simultaneously. They can also compute approximate answers to simple addition and subtraction events (e.g., 1+1 = 2; 5+5=10), judge which of two quantities is larger, and even compute fractions!
Like objects and people, numbers are important. They are ubiquitous in our environment (think of all the things you can count just in the room you're sitting in) and, in our evolutionary history, being able to represent and compare different quantities -- of two patches of food, of the size of an invading army, of the number of offspring we have -- has been critical to our survival. Given the adaptive advantages enjoyed by those that can represent and manipulate numbers, it's no wonder that that Mother Nature has built an understanding of number into our brains.
I began by declaring, rather shamelessly, that babies are smart. They are smart not only because of the immense amount of information they manage to learn in a lifetime, but because they begin life with useful knowledge in a set of core domains that over our evolutionary history have been selected for in the same way that hearts and lungs were selected for. The next time you gaze into your baby's eyes, and wonder what's going on in their little head, you can imagine that instead of a "blooming, buzzing, confusion," your baby sees you and probably knows a lot more about the world than you think.