The “terrible twos,” young children telling lies, teenagers’ heavy sarcasm — the list of different kinds of youthful behavior that adults struggle with is long. Other characteristics are more charming but equally mysterious: The way toddlers reveal themselves easily when playing hide and seek, the way young children thrill when shouting “He’s behind you,” their fascination with magic tricks.
What’s going on in children’s minds? Many of these events — the annoying, the charming, the dubious — reflect important steps in cognitive development. All reflect children’s emerging understanding of people’s minds. Children’s growing awareness of other people’s thinking is called a “theory of mind.” Developing a personal theory of mind requires extended learning by a child and partial accomplishments, punctuated by important advances. Theory of mind is a factor in children’s satisfying or unsatisfying friendships, their ability to accept feedback from teachers, and their ability to stand up for their own opinions, including arguing with, persuading, and negotiating with others. In fact, many of the ways our kids can be annoying — as well as charming, odd, and curious — prove essential for their social development.
An early annoying phase most children manifest has a name that they very often live up to: The “terrible twos” are an explosion of expressed, willful desire and intentions. This reflects a child’s determination to do what they desire, rather than what adults want. But this is in the service of their exploration of and learning about self and other. When a two-year-old throws his shoes around the supermarket, or says “no, no, no” to every parental desire or command, mom or dad may be exasperated. But adults can feel some reassurance in that this behavior also indicates healthy growth for the child.
In a classic experiment, known as the “Broccoli-Goldfish” study, researchers at the University of California, Berkeley showed that, even at 18 months, toddlers can understand adults’ desires and intentions and appreciate that these may be different from their own. The young children were offered two treats — a crown of broccoli or a Goldfish cracker. The children almost always preferred the Goldfish crackers. Then they watched the treats being offered to an adult, who said “Oh, yummy” to the broccoli and “Ew, yuck” to the cracker.
The following originally appeared in a different format on the Child & Family Blog, transforming research on cognitive, social, and emotional development and family dynamics into policy and practice.
When children then had the chance to give the adults a treat, they did not merely offer a Goldfish cracker — the treat they would want. Instead, they gave the adult broccoli. Even at this early age, children can understand diversity of desire and intentions among others. They know that everyone is not the same. This insight fuels the “terrible twos,” but also helpful, comforting behaviors to others.
Later, children gain additional understandings. They appreciate, crucially, that people’s actions are driven not only by desire and intention but also by knowledge and beliefs. They understand that what people know or don’t know about the world — think and don’t think — is also important. Two levels of skill develop around the ages of three and four. First, children begin to understand diversity of knowing — they recognize they might know something but another person might not. Next, they learn that beliefs differ and can be false.
When my son was around three and a half, he once told me: “Shut your eyes, Dad.” “OK, why?” I asked. “I’m going to do something you don’t like,” he replied. He showed me here that he understood that concealment could help him get what he wanted: I wouldn’t know so I wouldn’t object. That’s a good stratagem, driven by the theory of mind. But he didn’t yet appreciate that I needed to remain ignorant for his approach to work.
You can see this play out in simple games of hide and seek. At two and three years old, kids will hide in plain sight or, within a few moments of hiding, shout out where they are, unable to foster ignorance about their whereabouts.
The next level is for children to understand not just knowledge and ignorance, but belief, namely that beliefs differ for different people and from reality. So beliefs can be false.
When he was three and again at five, my son revealed this skill around belief when he tried a classic test in my child laboratory at the University of Michigan. He was shown two boxes. One was a candy box, the other was plain white. When I asked him what was in the candy box, he said, “Candy!” But, when he opened the box, he found it was empty. Instead, the plain box was full of candy.
I closed the boxes back up as Glenda, my research assistant, came in. “Glenda loves candy,” I told my son. Glenda nodded enthusiastically. Then I asked, “Where will Glenda look for candy?” At three, my son said, like almost all children at that age would, that Glenda would look for the candy in the plain box, because he knew that’s where the candy really was. He failed this false-belief task.
At this age children can understand someone’s wants. But when it comes to understanding thoughts, they often figure that everyone shares the same thoughts. They know where the candy really is, so, of course, they reckon Glenda does too.
But what about 5-year-old children? Eighty percent of them predict Glenda will look in the candy box. With a year and a half of additional development under their belts, children can now understand Glenda’s thinking. Her thoughts don’t just reflect the world. Instead, if she wants candy, she looks where she thinks it should be — in a candy box. They’ve figured out Glenda’s actions would be driven by her beliefs (in this case her false belief) rather than by where the candy really was.
Understanding false belief enables children to recognize that people can lie, and that they themselves can tell a falsehood. Theory-of-mind research has confirmed this link. Although lying is usually something parents worry about and discourage, it reflects an important insight. When young children tell lies, they’re trying out this insight into — experimenting with — what they have learned about themselves and other people’s minds. Fortunately, understanding how people come to their beliefs and misbeliefs also allows children to communicate more effectively, to persuade and negotiate, and it predicts better relationships with their peers.
Moreover, not all lies are dubious. We all appreciate “white” lies — we recognize that polite deceptions can aid positive relationships. Thus parents admire and encourage their children’s sophistication in telling grandma that she’s given them a wonderful Christmas present, even though they don’t actually like it. Learning how to lie appropriately reflects a big developmental step forward in understanding minds and in social skill. Importantly, these same skills — lying, white and “black,” persuading and negotiating — help children make their transition to school.
Understanding the minds of others doesn’t end with the transition to school. When children reach 13 or 14, they typically experiment with knowledge and beliefs in further, still more complicated, ways. A prime example is the understanding and use of sarcasm and irony. As much as the “terrible twos” can vex parents of younger children, incessant sarcasm can exasperate the parents of teens. Some teenagers seldom use a literal reply: “Time to wake up — Perfect! I love getting up in the dark.” “Eggs for breakfast again, my favorite.” A rainy day for a family outing: “Great, couldn’t be better. What a fabulous day!” Some teens can be so sarcastic and archly ironic that you never know if they’re giving you a compliment or they’re ready to go ballistic.
And among their peers, teenagers trade sarcasm with their friends. It’s part of bonding — it’s the coin of the realm. So are other ubiquitous forms of non-literal language: a really great song is “sick;” “spilling the tea” means gossiping.
It takes more than recognizing ignorance or false belief to understand and to communicate like this. If someone says (sarcastically), “What a great day,” when it’s raining, that doesn’t mean they’re ignorant and don’t know what the weather is. It doesn’t mean that they’re deceived. Nor does it mean they’re lying and trying to deceive you. This is a non-literal way to point out truths about the world.
A younger child might think such messages are lies or ignorance. Understanding sarcasm takes learning and development. And when that first comes, it gets exercised.
These developing skills, again, have implications for children’s social lives. Kids who don’t get sarcasm and slang may be excluded, stigmatized and considered stupid. They may experience misunderstandings, confused interactions, or even depression and hostility. Theory-of-mind research confirms these links as well.
What’s the big message for parents? Development works. As children learn and know more, they get beyond the “terrible twos,” they learn polite deceptions, and they outgrow incessant sarcasm. They learn and grow.
Adults can help their children learn and grow by talking about the mind with them. Research shows that more “mental talk” — who likes what and who doesn’t, who knows or thinks what — leads children to better understand minds. And remember, better understanding of minds helps children have better friendships and better transitions to school, and, in the long run, be less prone to depression.
Children are interested in these topics. They are distinctly interested in who does what and why. This helps explain why we adults become such inveterate gossipers. You can get a sense of this from children’s questions and their search for explanations. In everyday conversations with parents and others, children ask a lot of questions. Indeed, the myriad childhood “whys” can be as exasperating as incessant battles of will and sarcastic replies. The primary thing young children ask why about is why people do things: “Why do some people eat snails?” “Why is buttface a bad word?” “Why do people kill cows?”
Giving explanations rather than non-explanations helps children learn. In fact, asking children to provide their own explanations also helps. Educational researchers call this the self-explanation effect: Just asking children why 4 plus 4 equals 8 and not 5 helps them to learn and remember. The self-explanation effect appears for learning math, for learning science, for learning history, and for learning about people.
Fostering social intelligence, not just academic skills, is also crucial for learning and succeeding in school: Learning is not all about facts and procedures. It requires social-communicative exchanges; it requires being receptive to feedback; it benefits not just from being instructed but also from attempting to instruct others. It relies on theory-of-mind insights and advances. Enhanced theory of mind aids children in school — and in life — indirectly and directly.
Dr. Henry M Wellman is a professor of psychology at the University of Michigan, where he focuses on how infants, preschoolers, and older children learn about the social world and in particular how they acquire theory of mind. His recent book on these topics, Reading Minds: How Childhood Teaches Us to Understand People, is available now.