Campus & Community

Looking for the nature of human nature

7 min read

We’re born with a lot on our minds

Steven Pinker, a best-selling author and psychologist, studies the connections between brain, language, and mind, and wonders why people believe in a soul that is separate from the body. (Staff photo Stephanie Mitchell/Harvard News Office)

Steven Pinker is looking into peoples’ brains to try to see what’s on their minds. The Johnstone Family Professor of Psychology at Harvard disagrees with those who think that, at birth, it’s nothing.

Some people assume that a new mind is like a blank slate. Interactions with family, toys, media images, and whatever else is in the environment create impressions on the slate that make you what you are. Pinker wonders why that idea has had so much appeal. “Many studies suggest that we are born with our brain already wired to learn language,” he notes. “There is also evidence that we come into the world with certain expectations about objects, space and numbers, and with a capacity for emotions, such as love, hate, anger, and disgust.”

Pinker is skeptical, however, of the claim that human brains come with a “God module,” an innate capacity for belief in an all-knowing Grand Designer. Does the mind have a soul, or does it make one up?

One of Pinker’s favorite examples of research leading to the conclusion that a new mind isn’t blank comes from a study done by Nancy Segal, now a visiting scholar at Harvard, and her collaborators. It involves pairs of identical twins separated at birth. One twin of a male set was brought up as a Catholic in a Nazi family in Germany, the other was raised as a Jew by an adoptive father in Trinidad. When they finally met in their 40s, they were wearing identical blue shirts with epaulets. Both had rubber bands around their wrists. Both flushed the toilet before using it as well as after. Both liked to sneeze in crowded elevators to watch other people jump.

The minds of twins

Pinker’s own research includes a twins’ study that focuses on why some kids acquire language more quickly than others. He and his colleagues track several hundred pairs of twins, whose mothers keep diaries of their language development.

It turns out that identical twins, who both have the same genes, are more closely synchronized in language development than fraternal twins, who only share half their genes. That’s evidence, Pinker insists, for a genetically influenced clock, that is, for brain slates that come with rules for language development.

A related area of his research deals with how children use grammar. They apparently come into the world trying to master rules that call for adding “ed” to a verb to form a past tense. If you want the past tense of “talk” or “walk,” you just add “ed.” “Mommy talked to me.” “Daddy walked the dog.”

But what about all those irregular verbs like “go,” “bring,” and “find”? Children usually start by overapplying the rule and saying things like, “doggie goed,” “daddy bringed,” “I finded.” This shows that they are not just imitating their parents’ speech. Rather, they have unconsciously ferreted out a rule of grammar and are applying it creatively, albeit incorrectly. Some kids start making such errors before age 2, others don’t do it until they are almost 3. Pinker and his colleagues have found evidence that some of this variation depends on the ticking of the genetic clock.

A similar test examines when children begin to put together microsentences like “all gone milk,” “want cookie.” They don’t hear their parents say things like that, so they must be combining language elements in their own minds. Putting together such sentences represents the first glimmer of grammar. This, too, apparently depends of the organization of their not-so-blank slates.

“Parents often write to me to ask why their child is not talking yet,” Pinker notes. “They worry that it’s their fault for not talking enough to the child.” He assures them that there’s not necessarily anything wrong, it may be just a matter of timing, when genes turn on and off.

A full slate

What else might be on the slate besides an ability to learn rules for breaking sounds into words and combining them in sentences?

Experiments by Elizabeth Spelke, a professor of psychology at Harvard, suggest that babies come into the world with certain expectations about the stability of objects and with some knowledge about laws that govern them. Given the task of locating themselves after being turned around in a room, infants appear to locate themselves and objects by using cues like the shape of the room. Adults don’t orient themselves this way, but rats and hamsters do. This suggests that newborns have a primitive inborn capacity that gives them information about objects before they learn about them from parents or experience.

Spelke’s work also hints that we come into the world with some concept of numbers, possibly inherited from our evolutionary predecessors. When two objects are placed in a box, infants will reach in twice, not once or three times. Monkeys do the same thing, as demonstrated by Spelke’s and Pinker’s colleague, psychologist Marc Hauser. It appears that both infants and monkeys can add or subtract numbers up to three without any help from their parents.

To the list of things that might be on a newborn’s mind, Pinker adds an ability to conceive of other people as having their own thoughts and feelings, rather than as objects like robots or wind-up dolls. That’s a capability lacking in children with autism, an inherited deficit. In other words, autistic kids lack the genetically shaped intuition written on a normal slate.

Finally, Pinker believes, humans are born with some capacity for emotions and social relationships. He believes this involves things like love, hate, guilt, anger, disgust, gratitude, and a capacity for trust and solidarity toward friends and family.

Gods in your head

Pinker draws the line at an inborn belief in God or gods. He doesn’t look for this God module in brain scans, but he does discuss the subject in his 1997 book “How the Mind Works.” (He also continues to gets lots of mail about it.) In his latest book, “The Blank Slate: The Modern Denial of Human Nature,” he takes on the larger question of why many people believe in a soul that is separate from the physical activity of the brain, something for which, he says, no evidence exists.

Pinker notes that a God module in the brain fails to offer any direct evolutionary advantage, as counting and language do. “So, it’s likely,” he comments, “that religious belief is a byproduct of other faculties of the mind. If the mind explains the behavior of other people by positing they have minds, it’s a short step to posit that minds, like souls and spirits, aren’t tied to other peoples’ bodies.”

Pinker also argues that religion should not be considered a source of higher ethics and moral guidance. He points out that religion “has given us stonings, witch burnings, crusades, inquisitions, jihads, fatwas, suicide bombers, and mothers who drown their children.” He cites passages from the Bible that, he believes, make it “a manual for rape, genocide, and the destruction of families.”

Views like that have won him such honors as Humanist Laureate and the Emperor’s New Clothes Award from the Freedom from Religion Foundation.

Pinker himself considers looking at religious beliefs from a nonreligious point of view as part of solving the puzzle of how human nature works. “In my research and thinking about the brain, language, and mind,” he explains, “I’m trying to determine what the mind is and how it fits into a larger, coherent, scientific picture of the nature of things.”