Each of us begins to learn about personality at a very young age. During our childhood, most of us have the opportunity to learn important lessons about how people operate. Alternatively, our skills in the area may remain undeveloped and our ideas about personality misinformed. Depending on what we learn, we’ll be able to use our personal intelligence—our understanding of personality—in ways that benefit us or not. 

Developmental psychologists believe that children with more accurate theories of personality often have better relationships with others and that young people's concept of personality may also contribute to their ability to achieve in school. How do we learn about personality?

Young children actively absorb a wide range of information about the world around them. When it comes to personality, their learning is informal but grows quickly, much like their knowledge of vocabulary and intuitive physics.

Here are six key lessons about personality that preschoolers learn:

Lesson 1: People are Discrete Individuals

Each of us has a personality, but infants need to be able to tell people apart before they can assess an individual’s mental qualities. Mariko Moher and her colleagues at Johns Hopkins University have concluded that by four years of age, children can quickly create multimodal representations of the individuals around them—connecting voices and faces, that they also know that one face has one voice, and that they retain these multimodal representations of individuals in memory.

Lesson 2: People know Different Things

A key difference among individuals is that we know different things. One child may know a lot about the internet whereas another may know about bicycles and cars. Preschoolers understand that they may know things other children don’t. They’ve learned that “perceiving” leads to knowledge—that a person who sees something happen knows more about it than someone who doesn’t see it. They know that children who are watching the teacher play with the classroom hamster will know that the play took place, whereas a child who is absent that day will not.

Lesson 3: The Basic Vocabulary of Mental States

To understand others' personalities we need to know something about their feelings, desires, and aims. In 1982, Inge Bretherton and Marjorie Beeghly, now at the University of Wisconsin and Harvard Medical School, respectively, reported that many 28-month-old children were already able to use mental state terms correctly: Most commonly, children assessed physical states such as describing people as hot or cold, hungry or sick. But they also were able to describe people around them as sad or happy and provide occasional cognitive self-descriptions: “I think Mommy is tired.” They expressed needs such as “I have to play,” and “I want to go out to dinner”—and they were beginning to label others, “Lisa bad.”

We use our personal intelligence to realize that there are many similarities between ourselves and other people. James Mark Baldwin, a founder of North American psychology wrote in 1911, that for children, their “…subjective is made over to others.” In Bretherton and Beeghly’s study of children’s mental state language, the researchers reported that as children began to describe their own mental states, they quickly learned to apply those states to others.

Lesson 4: Learning to Connect Acts to Mental Traits

By age four, many children know about traits. David Liu, Susan Gelman and Henry Wellman of the University of Michigan demonstrated that four-year-olds were able to generalize from a single behavioral clue to correctly label a corresponding trait.  

In their experiment, the researchers told children a story about “Bobby,” a boy who didn’t share the cookies in his lunch with another child who asked for some. The experimenter then asked if Bobby was selfish or not. If the child answered yes, the researcher asked if Bobby was “a little selfish” “medium selfish” or “very selfish.” Children could correctly label Bobby as selfish when he failed to share and their judgments related to selfishness rather than just liking or disliking Bobby. (A statistical adjustment was made for liking to ensure that the children's understanding went beyond a positive or negative feeling). Children also could make connections between behaviors and the traits “nice,” “mean” and “shy.” In essence, the children could view a behavior and apply a descriptive trait to it.

Lesson 5: Learning to Connect Mental Traits to Acts

In another experiment, Liu and colleagues told the children that a person had a certain trait—“Eddie is selfish”— to see if the child would take the trait into account when deciding how Eddie would behave when he discovered his sister playing with his toys: Would he ask her to stop or give her more toys to play with?

Many children as young as four correctly predicted that Eddie would ask his sister to stop; older children were even more accurate at predicting his behavior. This research indicates that even young children reason about traits and predict behavior from them.

These developmental studies raise an obvious question for me: Why do we need trait terms like “selfish” or “nice” or “shy” at all? Why don’t we just generalize from behavior to behavior without using trait words? If we see Bobby refuse to share his cookies, why couldn’t we then reason that Bobby won't share his toys? Bobby might have declined to his cookies for many reasons aside from selfishness. Perhaps he was very hungry or maybe the child who asked had refused to share with Bobby earlier in the morning. Trait language elaborates behavior by suggesting an inner tendency that goes along with it. It steers an accurate perceiver toward making more correct attributions.

Lesson 6: Learning Models of Other People

Young children create models of their parents and other significant caretakers and how they behave. They use these models for understanding other people as they form new relationships in ever-widening circles as they grow.

From the perspective of personal intelligence, the children are picking up basic characteristics of key people and learning to apply those to similar new people they meet.

Better and Worse Learning

Children can learn these lessons well, can miss the point or become biased in their perceptions. If members of the child’s entourage—her parents, siblings, friends—are ‘miscalibrated’ from the norm in some way, the child's basic interpersonal sense of the terms may be a kilter. For example, if parents always give a child what she wants when she says, “I want [something],” she’ll lack judgment about the appropriateness of her requests and other people might come to regard her as spoiled. If people in a family are very outgoing, then a child who is average in extroversion could be mislabeled as shy. The idea of how to respond to “I want” or what's actually shy may vary somewhat from community to community.

If a child doesn’t learn to express “I want” at the right time with the right people, his needs are unlikely to be met. And if a child doesn’t perceive which friends are generous or not, he won’t know who to go to for help, or he may take another child’s refusal to help too personally, when the other child is merely less generous than others.

Learning about personality at a young age is important—and it teaches us something about what we know as adults and why we need to know it. Adults translate a person’s acts into presumed traits and then use those traits to predict the person’s future behavior. That act-trait-act translation guides how we anticipate the way other people will act in the future. There is great significance to our ability to anticipate how other people will behave: If we can do it well, we can better meet our needs when interacting with others and won't be unpleasantly surprised by what the people around us do.

Four-year-olds are just beginning to master this. They can reason from actions to a few traits and from traits to a few actions. They are less good at anticipating what people might do in many instances than are older children and adults. If parents talk about needs, wants, feelings and thoughts, they may enhance their children’s learning in these areas (I review some of the relevant research in Chapter 6 of the book Personal Intelligence).

By elucidating these learning processes we may be able to help some children who have trouble with these concepts to learn about personality. Equally significant, developmental studies, such as those described above, teach us how adults have come to learn about personality, the forms of reasoning adults employ, and the significance of applying their reasoning power to guiding their lives—the personal intelligence of our everyday lives.


Moher, M., Feigenson, L., Halberda, J. (2010). A one-to-one bias and fast mapping support preschoolers learning about faces and voices. Cognitive Science, 34, 719-751.

The quotes from Bretherton and Beeghly are from p. 914 and Table 2 on p. 918. Bretherton, I. & Beeghly, M. (1982). Talking about internal states: The acquisition of an explicit theory of mind. Developmental Psychology, Vol 18(6), Nov, 1982. pp. 906-921.

Baldwin, J. M. (1911). The individual and society. Boston: The Goreham Press.

Liu, D., Gelman, S., & Wellman, H. (2007). Components of young children's trait understanding: Behavior-to-trait inferences and trait-to-behavior predictions. Child Development, 78, 1543-1558.

Copyright © 2014 by John D. Mayer

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