Cognitive & Language Development

Early childhood is also a time of great development in the areas of cognition, language, and theory of mind (Bjorklund, 2022; Rakoczy, 2022). This chapter provides an overview of the these developments, as framed by theories of two of the greatest developmental scientists who ever lived: Jean Piaget and Lev Vygotsky (Flavel, 1963; Stoltz et al., 2024; Wertsch & Sohmer, 1995). Because this is such an important period of development, many preschool programs and curricula have been designed to support young children. This section ends with evidence of the effectiveness of such programs and an overview of developmentally-adapted educational practices (Von Suchodoletz et al., 2023).

Piaget’s Preoperational Stage

Building on the accomplishments of the first stage of cognitive development, which takes place during infancy and involves sensorimotor regulations, preschoolers enter the second stage of cognitive development, called the preoperational stage, which is organized around symbolic regulations. According to Piaget, this stage occurs from the age of 2 to 7 years. In the preoperational stage, children develop the capacity for symbolic thought, that is, they become able to use symbols to represent words, images, and ideas.

This development ushers in the use of language and children begin to engage in pretend play. With language, words are used as symbols to represent real objects and actions. And with pretend play, a child’s arms might become airplane wings as she zooms around the room, or a child with a stick might become a brave knight with a sword. However, despite these important developments, young children's cognition still had its limitations. They cannot yet understand adult logic or mentally manipulate information. The term operational refers to logical manipulation of information, so children at this stage are considered pre-operational. Children’s logic is based on their own personal knowledge of the world so far, rather than on conventional reasoning.

The preoperational period is divided into two substages:

1. The symbolic function substage occurs between 2 and 4 years of age and is characterized by gains in symbolic thinking, in which the child is able to mentally represent an object that is not present, and a dependence on perception in problem solving.
2. The intuitive thought substage, lasting from 4 to 7 years, is marked by greater dependence on intuitive thinking rather than just perception (Thomas, 1979). This implies that children think automatically without using evidence. At this stage, children ask many questions as they attempt to understand the world around them using the kinds of reasoning that are available to them. Let us examine some of Piaget’s assertions about children’s cognitive abilities at this age.

Pretend Play

Pretending is a favorite activity at this time. A toy has qualities beyond the way it was designed to function and can now be used to stand for a character or object unlike anything originally intended. A teddy bear, for example, can be a baby or the queen of a faraway land. Piaget believed that pretend play helps children practice and solidify new schemata they are developing cognitively. This play, then, reflects changes in their conceptions or thoughts. However, their play does not simply represent what they have already learned. Children also learn as they pretend and experiment (Berk, 2007).

Symbolic Function Substage (age 2-4 years)

The development of symbolic representation revolutionizes the way young children can think and act. Representational capacities underlie the emergence of language which opens up channels of communication with others and provides young children words and concepts for their own inner experiences (like emotion labels). Symbolic capacities also scaffold the development of memory, and allow young children to remember and discuss autobiographical events. They become very interested in two dimensional representations, like photographs and computer screens, and can interact with grandparents and others using these tools.

As seen at the end of the sensorimotor period, toddlers begin to use basic representations to solve problems in  their heads. During the preschool years, cognitive advances allow them to get better and better at trying out strategies mentally before taking action. Hence, planning and problem-solving become central activities. Problem-solving can be used to facilitate physical play (e.g., planning how to build a castle), solve interpersonal conflicts (e.g., two children want the same toy), or figure out how to comfort oneself when one is sad.

Mental  representations are also key to the advances in executive function and self-regulation described earlier (Inzlicht et al., 2021). When children can hold goals in their minds that are different from the ones that spontaneously emerge, they use representations of what they are supposed to do to modulate or manage what they want to do. Young children show an outpouring of representational activities, including language, pretend play, story telling, singing, drawing, looking a photos, and discussing the past and present. They love to engage in joint problem-solving and be read to, often asking for the same book or video over and over again, pouring over and discussing the story, until they can repeat every word.

Limitations in Preoperational Reasoning

Despite the many advances that symbolic thought brings to young children, there are still several significant limitations to their thinking, including egocentrism, perceptual salience, and animism. When parents see behaviors typical of the preoperational stage, it is important that they correctly interpret their meaning. Young children are not being hard to get along with. These behaviors are the result of genuine limitations in their cognitive functioning. Young children can understand many ideas and follow rules, but for the best developmental outcomes, adults should temper their expectations and demands so that they are reasonable, and explain their thinking using language that is developmentally attuned to children's current cognitive capacities.

Egocentrism. Egocentrism in early childhood refers to the tendency of young children to believe that everyone sees, thinks, and feels just as they do; they cannot yet take the perspective of others. Egocentric children are not able to infer the perspective of other people and instead attribute their own perspective to everyone in the situation. For example, ten-year-old Keiko’s birthday is coming up, so her mom takes 3-year-old Kenny to the toy store to choose a present for his sister. He selects an Iron Man action figure for her, thinking that if he likes the toy, his sister will too.

Piaget’s classic experiment on egocentrism involved showing children a three-dimensional model of a mountain and asking them to describe what a doll that is looking at the mountain from a different angle might see (see Figure 5.2).

Children tend to choose a picture that represents their own, rather than the doll’s view. By age 7 children are less self-centered. However, even younger children tend to use different sentence structures and vocabulary when addressing a younger child or an older adult. This indicates some basic awareness of the views of others.

Perceptual salience. Perceptual salience means that children reason, not based on what they know, but based on what they directly perceive (i.e., see and hear) in the immediate context. This cognitive limitation is on display every Halloween, when parents dress up, especially if they use masks. For a preoperational child, the mask is so perceptually salient that even if the parent continues to talk and the child can recognize their voice, their experience is so overwhelmed by the transformation of the parent's face, that they can react to the masked parent as if they were a stranger. At this age, children's understanding is halfway between the reasoning based on action of the sensorimotor period and the reasoning based on logic of the concrete operational period. During the preoperational period, reasoning is based on empirical reality, that is, information provided by the senses.

Animism. Animism refers to attributing life-like qualities to objects. The cup is alive, the chair that falls down and hits the child’s ankle is mean, and the toys need to stay home because they are tired. Cartoons frequently show objects that appear alive and take on lifelike qualities. Young children do seem to think that objects that move may be alive, but after age three, they seldom refer to objects as being alive (Berk, 2007).

Intuitive Substage (age 4-7 years)

During the intuitive substage, children begin to move toward logical thinking. They show some signs of logical reasoning, but can't explain how or why they think as they do. This is an age filled with questions, as children begin to make sense of their worlds. Parents should know that children's ceaseless "why?" questions do not require detailed explanations. They are looking for brief and simple explanations.

For example, if children ask "Why do I have to wear a helmet when I ride a bicycle?" they are not looking for a lecture on legal issues, but just a simple "To keep your head safe." Likewise, if they come back from a bike ride and say "Well, I didn't fall down, so now I don't need to wear a helmet any more", you can explain the idea of risk through an everyday example, saying, "You have to wear it every time, because you could fall down." If you want to try a metaphor, you could explain, " Your head is like a glass, it could get broken. Does a glass break every time you drop it? No. But does that mean that it's a good idea to drop a glass? No. We want to keep your head safe."

Centration. The primary limitation of thought during the intuitive substage is called centration. Centration means that understanding is dominated (i.e., centered on) a single feature of an object-- the most perceptually salient one. At this age, children cannot hold or coordinate two features of an object at the same time. Piaget demonstrated this aspect of preoperational thought in a series of experiments. They showed that young children do not yet have the logical notion of conservation, which refers to the ability to recognize that aspects like quantity remain the same, even when over transformations in appearance. 

Inability to conserve. Using Kenny and Keiko again, dad gave a slice of pizza to 10-year-old Keiko and another slice to 3-year-old Kenny. Kenny’s pizza slice was cut into five pieces, so Kenny told his sister that he got more pizza than she did. Kenny did not understand that cutting the pizza into smaller pieces did not increase the overall amount. This was because Kenny exhibited centration when he focused on only one characteristic (the number of pieces) to the exclusion of others (total amount).

Kenny's reasoning was based on his five pieces of pizza compared to his sister’s one piece even though the total amount of pizza each had was the same. Keiko did not agree that Kenny had more pizza. Shewas able to consider several characteristics of an object-- understanding that amount did not change just because there were more pieces. Because young children have not developed this understanding of conservation, they cannot perform mental operations.

The classic Piagetian experiment associated with conservation involves liquid (Crain, 2005). As seen on the left side of Figure 5.3, the child is shown two glasses which are filled to the same level and asked if they have the same amount. Usually the child agrees they have the same amount. The experimenter then pours the liquid in one glass to a taller and thinner glass (as shown in the center of Figure 5.3). The child is again asked if the two glasses have the same amount of liquid. The preoperational child will typically say the taller glass now has more liquid because it is taller (as shown on the right side). The child has centrated on the height of the liquid and fails to conserve its amount over this transformation.

Classification errors. Preoperational children also demonstrate centration when they have difficulty understanding that an object can be classified in more than one way. For example, if shown three white buttons and four black buttons and asked whether there are more black buttons or buttons, the child is likely to respond that there are more black buttons. They focus on the most salient feature (black buttons) and cannot keep in mind the the general class of buttons, so they compare black versus white buttons, instead of part versus whole.

Because young children lack these general classes, their reasoning is typically transductive, that is, making faulty inferences from one specific example to another. For example, Piaget’s daughter Lucienne stated she had not had her nap, therefore it was not afternoon. She did not understand that afternoons are a time period and her nap was just one of many events that occurred in the afternoon (Crain, 2005). As the child’s capacity to mentally represent and coordinate multiple features improves, the ability to classify objects emerges.

Critiques of Piaget

Similar to  critiques of the sensorimotor period, several psychologists have attempted to show that Piaget also underestimated the intellectual capabilities of the preoperational child. For example, children’s specific experiences can influence when they are able to conserve. Children of pottery makers in Mexican villages know that reshaping clay does not change the amount of clay at much younger ages than children who do not have similar experiences (Price-Williams, Gordon, & Ramirez, 1969). Crain (2005) also showed that under certain conditions preoperational children can think rationally about mathematical and scientific tasks, and they are not always as egocentric as Piaget implied. Research on theory of mind (discussed later in the chapter) shows that some children overcome egocentrism by 4 or 5 years of age, which is sooner than Piaget indicated (Rakoczy, 2022).

As with sensorimotor development, Piaget seemed to be right about the exact sequence and the processes involved in cognitive development, as well as when these steps are typically observable under naturalistic conditions. But current research has provided more accurate estimates of the exact ages when underlying capacities emerge, which could only be revealed by working with children in specific experimental conditions that removed typical contextual barriers to their performance.

Vygotsky’s Sociocultural Theory: Changes in Understanding with Guidance

Many modern social learning theories stem from the work of Russian psychologist Lev Vygotsky (Vasileva & Balyasnikova, 2019; Wertsch & Sohmer, 1995), who produced his ideas as a reaction to existing conflicting approaches in psychology (Kozulin, 1990; ). Vygotsky’s ideas are most recognized for identifying the role of social interactions and culture in the development of higher-order thinking skills (Taber, 2025; Topçiu, & Myftiu, 2015). His theory is especially valuable for the insights it provides about the dynamic “interdependence between individual and social processes in the construction of knowledge” (John-Steiner & Mahn, 1996, p. 192).

Vygotsky’s views are often considered primarily as developmental theories, focusing on qualitative changes in behavior over time, that attempt to explain unseen processes of development in thought, language, and higher-order thinking skills. Although Vygotsky’s intent was mainly to understand higher psychological processes in children, his ideas have many practical applications for learners of all ages (Newman & Latifi, 2021; Shabani, 2016; Stoltz et al., 2024).

Three themes are often identified with Vygotsky’s ideas of sociocultural learning: (1) human development and learning originate in social, historical, and cultural interactions, (2) the use of psychological tools, particularly language, mediates the  development of higher mental functions, and (3) learning occurs within the "zone of proximal development." While we discuss these ideas separately, they are closely interrelated.

Sociocultural Theory

Vygotsky’s sociocultural theory emphasizes the centrality of culture, including participation in culturally-scripted activities, social interactions between members of a culture, and cultural tools like language. Vygotsky contended that cognitive development has social origins, that social interactions play a critical role especially in the development of higher-order thinking skills, and therefore cognitive development cannot be fully understood without considering the social and historical context within which it is embedded. He explained, “Every function in the child’s cultural development appears twice: first, on the social level, and later, on the individual level; first between people (interpsychological) and then inside the child (intrapsychological)” (Vygotsky, 1978, p. 57). It is through working with others on a variety of tasks that a learner adopts socially shared experiences and associated effects and acquires useful strategies and knowledge (Scott & Palincsar, 2013; Taber, 2025).

Rogoff (1990) refers to this process as guided participation, where a learner actively acquires new culturally valuable skills and capabilities by collaborating on a meaningful activity with an assisting, more experienced other. It is critical to notice that these culturally mediated functions are viewed as being embedded in sociocultural activities rather than being self-contained. Development is a “transformation of participation in a sociocultural activity” not a transmission of discrete cultural knowledge or skills (Matusov, 2015, p. 315).

For example, young children learn problem-solving skills, not by sitting alone at a desk trying to solve arbitrary problems, but by working alongside parents or older siblings as they work on actual culturally-relevant tasks, like preparing a family meal or repairing a fence. Working together, the dyad or group encounter social and physical problems, and discuss their possible solutions before taking action. It is through participation in such joint problem-solving that young children develop these skills.

Language as a Developmental Tool

In his sociocultural view of development, Vygotsky highlighted the tools that the culture provides to support the development of higher-order thought. Chief among them is language. For Vygotsky, children interact with the world through the tool of language. For Piaget, children use schemas that they construct and organize on the mental plane, which are then expressed in language Stoltz et al., 2024).

But for Vygotsky language, a social medium, is the mechanism through which we build knowledge of the world. He believed that with development, the language we acquire from our environment shapes the ways in which we think and behave. With development, language becomes internalized as thought (i.e., cognition, or reasoning) and children use this internalized language to guide their action.

Scaffolding and the "Zone of Proximal Development" 

Vygotsky differed with Piaget in that he believed that a person not only has a set of actual abilities, but also a set of potential abilities that can be realized if given the proper guidance from others. He believed that through scaffolding, defined as a process in which adults or capable peers model or work together to solve a problem, and then step back, offering support as needed, a child can learn new cognitive skills. The zone of proximal development, defined as what a learner can do with help from more competent others, sits in the gap between what a learner can do alone without help, and what the learner cannot yet do. This zone represents an important site for development, since learning is optimized when children work on challenging but achievable tasks, with well-attuned assistance.

Both Piaget and Vygotsky highlighted the importance of interactions with the social and physical world as the sources of developmental change, Piaget’s ideas of cognitive development emphasized universal stages progressing toward increasing cognitive complexity. Vygotsky presents a more culturally-embedded view in which situated participatory learning drives development. The idea of learning driving development, rather than being determined by the developmental level of the learner, fundamentally changes our understanding of the learning process and has significant instructional and educational implications (Miller, 2011; Newman & Latifi, 2021; Stoltz et al., 2024).

Have you ever taught a child to perform a task? Maybe it was brushing their teeth or preparing food. Chances are you explained what you were doing while you demonstrated the skill, and let them work along with you throughout the process. You gave them assistance when they seemed to need it, but once they knew what to do, you stood back and let them go. This is scaffolding. This approach to teaching has also been adopted by educators (Newman & Latifi, 2021; stilts et al., 2024). Rather than assuming that what students can represents some fixed ability, their performance should be understood in terms of what they are capable of doing with the proper guidance and mentoring.

This difference in assumptions has significant implications for the design and development of learning experiences. If we believe as Piaget did that development precedes learning, then we will introduce children to learning activities involving new concepts and problems, but follow their lead, allowing learners to initiate participation when they are ready or interested. On the other hand, if we believe as Vygotsky did that learning drives development and that development occurs as we learn a variety of concepts and principles, recognizing their applicability to new tasks and new situations, then our instructional design will look very different.

Language Development

The development of symbolic representation during the second year of life leads to an explosion of language growth during toddlerhood and early childhood (Al-Harbi, 2020; Gleason & Ratner, 2022; Zauche et al., 2016). Language development itself also contributes to the development of executive function, emotional regulation, and other sociocognitive and academic skills (Lurie et al., 2021; Romeo et al., 2022).

Vocabulary growth. Between the ages of two to six, a child’s vocabulary expands  from about 200 words to over 10,000 words. This “vocabulary spurt” typically involves 10-20 new words per week and is accomplished through a process called fast-mapping. Words are easily learned by making connections between new words and concepts already known. The parts of speech that are learned depend on the language and what is emphasized (Zauche et al., 2016). Children speaking verb-friendly languages, such as Chinese and Japanese, learn verbs more readily, while those speaking English tend to learn nouns more readily. At the same time, some children learning less verb-friendly languages, such as English, seem to need assistance in grammar to master the use of verbs (Imai et al., 2008).

Literal meanings. Children can repeat words and phrases after having heard them only once or twice, but they do not always understand their meaning. This is especially true of expressions or figures of speech which are taken literally. For example, a classroom full of preschoolers hears the teacher say, “Wow! That really takes the cake!” The children may begin asking “Cake? Where is my cake? I want cake!” Or when a young child falls down and scrapes her knee, and she hears a parent say "Oh your poor knee" as they put on a band-aid, the parent should not be surprised if, when the child falls down and scapes an elbow, she shows it to the parent and says-- "Oh, man, I got another knee."

Overregularization. Children learn rules of grammar as they learn language but may apply these rules to all cases at first, even ones where the do not apply. For instance, a child learns to add “ed” to the end of a word to indicate past tense. Then forms a sentence such as “I go-ed there. I do-ed that.” This is typical at ages two and three. Even without any correction, those mistakes will soon disappear, and they will learn new words such as “went” and “did” to be used in those situations.

Supporting language development. Remember Vygotsky and the zone of proximal development? The most important way to assist children in language learning is to make sure they experience a language-rich environment (Zauche et al., 2016). Language competency is dependent on the quantity, quality, and opportunity to use a language (Hoff, 2018).  Although passive exposure is helpful, children learn best through direct communication, when language is directed at them individually and others listen attentively, model more accurate pronunciations and encourage elaboration. The child exclaims, “I’m goed there!” and the adult responds, “You went there? Where did you go?”

No corrections are needed. Children are ripe for language, as Chomsky suggests, and active participation in ongoing conversations with caring others promotes their language development. The process of scaffolding is one in which the guide provides needed assistance to the child as a new skill is learned. The most important scaffold for young children is talking to someone, which of course includes being listened to, paid attention to, and talked to as well (Attanasio et al., 2022).

Bilingualism

Although monolingual speakers often do not realize it, the majority of children around the world are bilingual, meaning that they understand and speak two (or more) languages (Meyers-Sutton, 2005). Even in the United States, which is a relatively monolingual society, more than 68 million people (about 20% of the population) speak a language other than English at home, including 42 million Spanish speakers, according to 2019 data from the US Census Bureau (Camarota & Zeigler, 2014; Ryan, 2013).

Children who are dual language learners are one of the fastest growing populations in the US (Hammer et al., 2014). They make up nearly 30% of children enrolled in early childhood programs, like Head Start. When children here in the US are learning a language other than English from their family's culture(s) of origin, this is called a heritage language and they are heritage speakers. Young children of monolingual parents can also become bi- or multi-lingual by attending language immersion preschools.

By the time they enter elementary school, children are very heterogeneous in their language and literacy skills, but bilingual children are no more likely to have delays or problems with language than monolingual children (Hammer et al., 2014; Paradis, 2023). The most straightforward pathway to becoming bi-lingual and bi-literate involves hearing both languages, but especially the heritage language, at home and attending immersion schools. Children also benefit from ongoing language support from parents, families, and their larger communities. For example, hearing stories, singing songs, reading books, and watching TV or movies in both languages helps children cement their understanding, speaking, and reading fluency.

Bilingual children may show slight delays in language learning. Because language competency is dependent on the quantity, quality, and opportunity to use a language (Hoff, 2018), dual language learners may hear the same number of words and phrases (quantity) overall, as do monolingual children, but it is split between two languages (Hoff, 2018). Thus, in any single language they may be exposed to fewer words. They will show higher expressive and receptive skills in the language they come to hear the most. In addition, children in bilingual households will sometimes avoid using the family’s heritage language in favor of the majority language (DeHouwer, 2007, Hoff, 2018). A common pattern in Spanish-English homes, is for the parents to speak to the child in Spanish, but for the child to respond in English. As a result, children may show little difference in the receptive skills between English and Spanish, but better expressive skills in English (Hoff, 2018).

Immigrant parents sometimes worry that learning their heritage language will interfere with children becoming fluent in the new culture's dominant language. However, young children are easily able to acquire multiple languages, and learning one will not interfere with learning another. Most important is to have rich language experiences in both. Sometimes parents also worry that, if they are not native speakers of a specific language themselves, then using their imperfect or accented version of the language will confuse children. However, even infants are able to filter out imperfections and acquire the language effectively.

Advantages of Bilingualism. There are several studies that have documented the advantages of learning more than one language in early childhood. For example, bilingual children consistently outperform monolinguals on measures of executive function skills, like inhibitory control, which involves ignoring irrelevant information (Bialystok, Martin & Viswanathan, 2005). Studies also reveal an advantage for bilingual children on measures of verbal working memory (Kaushanskaya, Gross, & Buac, 2014; Yoo & Kaushanskaya, 2012) and non-verbal working memory (Bialystok, 2011). However, it has been reported that among lower SES populations the working memory advantage is not always found (Bonifacci, Giombini, Beloocchi, & Conteno, 2011).

There is also considerable research to show that being bilingual, either as a child or an adult, leads to greater efficiency in the word learning process. Monolingual children are strongly influenced by the mutual-exclusivity bias, the assumption that an object has only a single name (Kaushanskaya, Gross, & Buac, 2014). For example, a child who has previously learned the word car, may be confused when this object is referred to as an automobile or sedan. Research shows that monolingual children find it easier to learn the name of a new object, than acquiring a new name for a previously labelled object. In contrast, bilingual children and adults show little difficulty with either task (Kaushanskaya & Marian, 2009). This finding may be explained by the experience bilinguals have in translating between languages when referring to familiar objects.

Educational Programs. Educational programs should take advantage of the preschool years as a time when children are developmentally primed to learn more than one language. The practice in the US of waiting until middle or high school to learn a second language flies in the face of the natural developmental progression of language learning. Systematic instruction, practice, reading, and writing in multiple languages would allow young children to become bilingual and bi-literate during a developmental period when that is relatively easy. That is why many school districts offer immersion programs in multiple languages starting in preschool and Kindergarten. School districts that serve many children who speak first languages other than English can take advantage of their skills and support bilingualism in all their pupils.

It is important to note that, although it is easier during early and middle childhood, people can learn languages at any age. So if you were not lucky enough to have been raised bilingual or multilingual, you should feel free to guide your own development by learning a new language. It opens doorways of understanding into your own heritage or other cultures, and is good for your cognitive flexibility and development!

Theory of Mind

Theory of mind refers to the ability to think about other people’s thoughts, also known as meta-cognition, that is, thinking about thinking. Theory of mind is the understanding that other people experience mental states (e.g., thoughts, beliefs, feelings, desires) that are different from our own, and that their mental states are what guide their behavior (Wellman, 2017, 2018). This set of skills emerges in early childhood (Poulin-Dubois, 2020; Rakoczy, 2022; Slaughter et al., 2016), but is a lifelong task (Meinhardt‐Injac et al., 2020). Theory of mind skills help humans to infer, predict, and understand the reactions of others, thus playing a crucial role in social development and in promoting competent social interactions (Imuta et al., 2016; Simon & Nader-Grosbois, 2025).

One common method for determining if a child has reached this mental milestone is called the False Belief Task. This research began with a clever experiment by Wimmer and Perner (1983), who tested whether children can pass a false-belief test (see Figure 5.5).

The child is shown a picture story of Sally, who puts her ball in a basket and leaves the room. While Sally is out of the room, Anne comes in and takes the ball from the basket and puts it inside a box.

Then Sally comes back into the room, and the child is asked where Sally thinks the ball is located. Is she going to look first in the box or in the basket? The right answer is that she will look in the basket, because that is where she put the ball and so she thinks it is still there.

But we have to infer this false belief against our own better knowledge that the ball is actually in the box. This is very difficult for children before the age of four because of the cognitive effort it takes.

Three-year-olds have difficulty distinguishing between what they once thought was true and what they now know to be true. They feel confident that what they know now is what they have always known (Birch & Bloom, 2003).

You could say that their perspectives are fused: Whatever is actually true is what they and everyone else thinks (and have always thought). Even adults sometimes need a minute to think through this task (Epley, Morewedge, & Keysar, 2004). To be successful, the child must separate three things: (1) what is true; (2) what they themselves think (which can be false); and (3) what someone else thinks (which can be false and can also be different from what they think). Can you see why this task is so complex?

In Piagetian terms, children must give up a tendency toward egocentrism. The child must also understand that what guides people’s actions and responses are what they believe rather than what is actually true. In other words, people can mistakenly believe things that are false (called false beliefs) and they will act based on this false knowledge. Consequently, prior to age four children are rarely successful at solving such tasks (Wellman, Cross & Watson, 2001).

Development of Theory of Mind

Researchers examining the development of theory of mind have been concerned by the overemphasis on the mastery of false belief as the primary measure of whether a child has attained theory of mind. Two-year-olds understand that different people have a diversity of desires, yet as noted earlier it is not until age four or five that children grasp false beliefs, and often not until middle childhood do they understand that people may hide how they really feel. In part, because children's understanding is fused: in early childhood children do not differentiate genuine feelings from the expression of feelings. They have difficulty hiding how they really feel (e.g., pretending to like a gift that they do not really like).

Wellman and his colleagues (Wellman, 2017, 2018; Wellman, Fang, Liu, Zhu & Liu, 2006) suggest that theory of mind is comprised of a number of components, each with its own developmental timeline (see Table). The idea that theory of mind is a set of skills is consistent with evidence showing that the development of executive function skills is closely related to the development of theory of mind (Andre & Maintenant, 2025).

Table 5.1 Components of Theory of Mind

adapted from Lally & Valentine-French, 2019

Young children in the US, Australia, and Germany develop theory of mind in the sequence outlined in the table. Yet, Chinese and Iranian preschoolers acquire knowledge access before diverse beliefs (Shahaeian, Peterson, Slaughter & Wellman, 2011). Shahaeian and colleagues suggested that cultural differences in child-rearing may account for this reversal. Parents in collectivistic cultures, such as China and Iran, emphasize conformity to the family and cultural values, greater respect for elders, and the acquisition of knowledge and academic skills more than they do autonomy and social skills (Frank, Plunkett & Otten, 2010). This could reduce the degree of diversity of opinions expressed in the family.

In contrast, individualistic cultures encourage children to think for themselves and assert their own opinions, and this could increase the variety of beliefs being expressed by family members. As a result, children in individualistic cultures would acquire insight into the question of diversity of belief earlier, while children in collectivistic cultures would acquire knowledge access earlier in the sequence. The role of divergent opinions in aiding the development of theory of mind could also account for the earlier age of onset of an understanding of false belief in children with siblings, especially older siblings (McAlister & Petersen, 2007; Perner, Ruffman & Leekman, 1994).

Theory of mind is also promoted through conversations about mental states (Bianco et al., 2016). Theory of mind skills are part of social intelligence, such as recognizing that others can think differently about situations. It helps us to be self-conscious or aware that others can think in different ways and it helps us to be able to be understanding or empathic toward others (Simon & Nader-Grosbois, 2025). Moreover, this "mind reading" ability helps us to anticipate and predict people’s actions. The awareness of the mental states of others is important for communication and social skills (Imuta et al., 2016).

Early Childhood Education

Providing universal preschool has become an important rallying point for parents and researchers (both developmental and educational) as well as for federal, state, and local leaders throughout our country. Head Start offers free preschool to 3- and 4-year-olds from low-income families. Early Head Start helps families in need, from pregnancy to age 3. Access to universal free or subsidized preschool programs differs on a state by state basis. Fully implemented universal free pre-Kindergarten (pre-K) programs for 4-year-olds are provided by only four states (Florida, Oklahoma, Vermont, and West Virginia) and the District of Columbia; Vermont also includes preschool programs for 3-year-olds. Many other states are in the process of implementing universal pre-K (which is for 4-5 year-olds) or preschool (for 3-5 year-olds), or already have programs that are subsidized or have income eligibility requirements (e.g., Wang et al., 2025). Six states have no state-funded or subsidized pre-K or preschool programs (Idaho, Montana, New Hampshire, North Dakota, South Dakota, and Wyoming).

For the latest information, the National Institute for Early Education Research offers a State of the Preschool Yearbook; the most recent covers 2024-2025.

Developmental and educational researchers are very interested in the role of pre-K and preschool programs in supporting young children's development. They have been providing evidence about what constitutes high quality preschool, and examining the effectiveness of preschools in fostering children's healthy development and preparing them for elementary school.

High Quality Early Childhood Education Programs

To set criteria for designation as a high-quality preschool, the National Association for the Education of Young Children (NAEYC) defines developmentally appropriate practice as methods that promote each child’s optimal development and learning through a strengths-based, play-based approach to joyful, engaged learning. As shown in the table, NAEYC identifies nine important standards for high quality early childhood education programs (NAEYC, 2025).

Parents can review preschool programs using criteria such as those set by NAEYC as a template for observing and asking questions that will assist them in choosing the best program for their child. Selecting the right preschool is not easy because there are so many types of preschools available. Zachry (2013) identified Montessori, Waldorf, Reggio Emilia, High Scope, Parent Co-Ops and Bank Street as types of preschool programs, approaches, and curricula that focus on children learning through discovery. Teachers act as guides and create activities based on the child’s developmental level.

Head Start

For children who live in poverty, Head Start has been providing preschool education since 1965 when it was begun by President Lyndon Johnson as part of his war on poverty. It currently serves nearly one million children and annually costs approximately 12 billion dollars (United States Department of Health and Human Services, 2023).

Developmental Impacts. Research paints a positive but complex picture of the effects of Head Start and other early childhood education programs (Bierman et al., 2017; Hines, 2017; Love et al., 2005; Von Suchodoletz et al., 2023; Welsh et al., 2020). In general, preschool programs support children's immediate socioemotional, self-regulatory, and academic development. Medium term, children who attend preschool also show improved school readiness and are less likely to drop-out or be involved in delinquency and other problematic behaviors during adolescence. Long-term benefits include a greater likelihood of graduating high school, attending college, and earning higher wages. The positive effects of participation in early childhood programs are more pronounced for children from low income, poverty, and racial and ethnic minority families, where they have been shown to reduce some of the underachievement and disparities in academic performance in these groups (Attanasio et al., 2022).

Research Challenges. At the same time, documenting the effects of Head Start and other preschool programs is a challenging empirical task (Meloy et al., 2019) and historically, research seems to show diminished effects, compared to initial implementation of Head Start (Whitaker et al., 2023). These issues are laid out very clearly in a 2019 report entitled, Untangling the Evidence on Preschool Effectiveness (Meloy et al., 2019).

There are three major problem in determining the effectiveness of Head Start or other preschool programs. The first is methodological. Studies use non-experimental designs. In order to see whether children who attend Head Start fare better, a comparison group is needed. Most informative, of course, would be comparable children who did not go to any preschool. For ethical reasons, however, researchers cannot exclude low income children from preschools, so comparison groups usually have had some type of pre-school programming in an alternative setting. Hence, much of the research examines the effects of Head Start only compared to other similar programs. When children who attend a specific program are compared to similar youngsters who did not attend preschool at all—as opposed to those who attended another program—the benefits of preschool are evident (Meloy et al., 2019).

A second problem is substantive. The preschool programs offered under the umbrella of Head Start are very heterogeneous. Programs differ depending on the location, and these differences include, for example, the length of the day and qualification of the teachers. It is especially important to determine whether programs are providing high-quality care. Higher quality programs, for example those meeting the NAECY standards described above, have been shown to have bigger short- and long-term impacts (Von Suchodoletz et al., 2023). In fact, a study examined the effects of adding enriched evidence-based programming (e.g., home visits) to regular Head Start programs, and discovered that these enrichments improved outcomes immediately (Bierman et al., 2017) and were sustained when children were in fifth graded (Welsh et al., 2020).

A third problem in examining longer-term outcomes is that, as discussed in the chapter on "higher-order contexts of parenting," children who are eligible for Head Start due to low family wealth are also more likely to attend elementary, middle, and high schools that are of lower quality and to live in neighborhoods that contain multiple developmental hazards. Thus, it may be more difficult for early improvements to be sustained. Researchers point out that ECE can support children's development, but it cannot "inoculate" them against educational and other risks they may subsequently encounter. As explained by Meloy and colleagues, "It is critical for policymakers to understand that the quality of early learning is important for immediate outcomes, but sustained benefits likely require more comprehensive investments in children and their families" (2019, p. viii).

Economic Impacts. Despite the challenges in researching the effectiveness of Head Start, the social and economic benefits of investing in universal preschool cannot be overstated. This is especially true for preschool programs that serve marginalized children and communities. Researchers and economists have estimated that investing in the cost of Head Start for a single child—about $17,000—can yield a return to society of between $300,000 and $500,000 over that child’s lifetime (Heckman et al., 2010).

Economic studies of the effectiveness of Head Start (e.g., De Haan & Leuven, 2020) suggest multiple ways in which these programs "more than pays for themselves," as described, for example in UCLA's Anderson review. Affordable and reliable child care improves family financial stability by allowing low income parents to pursue educational and employment opportunities; thus earning more money and requiring less public assistance.

Families with children attending Head Start do not use other federally or state funded programs, saving those monies. Lower rates of special and remedial education and grade retention save educational costs. A substantial economic return comes in the form of lower high school dropout rates, lower unemployment rates, and lower rates of incarceration-- all of which have been documented for individuals who had academic and social supports during early childhood (Heckman et al., 2010). Graduates earn higher wages, and so use less public assistance and make higher tax contributions. Children who attend Head Start even have better health as adults, saving healthcare costs.

Thus, in addition to their many benefits to human development, these programs save our society billions of dollars in the long run. Similar to the concept of preventative healthcare, the benefits of investing in early education for children in poor or underserved communities today will add up over time, and will yield greater societal benefits than we would expect from programs that implement interventions after problems emerge (for example, remedial schooling, job re-training, or substance abuse rehabilitation; Heckman, 2006).

Supplemental Materials

• This Ted Talk features a seasoned school teacher, who discusses the importance of building strong and positive relationships with students.

• This Ted Talk given by queer educator, Lindsay Amer, discusses why kids need to learn about gender and sexuality.

• This website offers queer educator, Lindsay Amer's teaching videos and resources to educate kids about gender and sexuality.

http://queerkidstuff.com/videos

• This study explores maternal involvement in the preschool years for Black families across three generations.

Jarrett, R. L. & Coba-Rodriguez, S. (2015). "My Mother Didn’t Play about Education”: Low- income, African American Mothers’ Early School Experiences and Their Impact on School Involvement for Preschoolers Transitioning to Kindergarten. The Journal of Negro Education, 84 (3 ), 457-472.

• This article compares Piaget and Vygotsky's perspectives on learning and development in a deep dive on constructivism.

Vianna, E., & Stetsenko, A. (2006). Embracing History through Transforming It: Contrasting Piagetian versus Vygotskian (Activity) Theories of Learning and Development to Expand Constructivism within a Dialectical View of History. Theory & Psychology, 16(1), 81–108. https://doi.org/10.1177/0959354306060108

References

Al-Harbi, S. S. (2020). Language development and acquisition in early childhood. Journal of Education and Learning (Edulearn), 14(1), 69-73.

Andre, M. L., & Maintenant, C. (2025). The role of executive function and language abilities in explaining theory of mind development in preschool-age children. Journal of Clinical and Experimental Neuropsychology, 47(3), 205-217.

Attanasio, O., Cattan, S., & Meghir, C. (2022). Early childhood development, human capital, and poverty. Annual Review of Economics, 14(1), 853-892.

Bialystok, E. (2011). Coordination of executive functions in monolingual and bilingual children. Journal of Experimental Child Psychology, 110, 461–468.

Bialystok, E., Martin, M.M., & Viswanathan, M. (2005). Bilingualism across the lifespan: The rise and fall of inhibitory control. International Journal of Bilingualism, 9, 103–119.

Bianco, F., Lecce, S., & Banerjee, R. (2016). Conversations about mental states and theory of mind development during middle childhood: A training study. Journal of experimental child psychology, 149, 41-61.

Bierman, K. L., Heinrichs, B. S., Welsh, J. A., Nix, R. L., & Gest, S. D. (2017). Enriching preschool classrooms and home visits with evidence‐based programming: Sustained benefits for low‐income children. Journal of Child Psychology and Psychiatry, 58(2), 129-137.

Birch, S., & Bloom, P. (2003). Children are cursed: An asymmetric bias in mental-state attribution. Psychological Science, 14(3), 283-286.

Bjorklund, D. F. (2022). Children′ s thinking: Cognitive development and individual differences. Sage publications.

Bonifacci, P., Giombini, L., Beloocchi, S., & Conteno, S. (2011). Speed of processing, anticipation, inhibition and working memory in bilinguals. Developmental Science, 14, 256–269.

Camarota, S. A., & Zeigler, K. (2015). One in five U. S. residents speaks foreign language at home. Retrieved from https://cis.org/sites/default/files/camarota-language-15.pdf

Crain, W. (2005). Theories of development concepts and applications (5th ed.). New Jersey: Pearson.

De Haan, M., & Leuven, E. (2020). Head start and the distribution of long-term education and labor market outcomes. Journal of Labor Economics, 38(3), 727-765.

De Houwer, A. (2007). Parental language input patterns and children’s bilingual use. Applied Psycholinguistics, 28, 411–422.

Epley, N., Morewedge, C. K., & Keysar, B. (2004). Perspective taking in children and adults: Equivalent egocentrism but differential correction. Journal of Experimental Social Psychology, 40, 760–768.

Flavell, J. H. (1963). Piaget's contributions to the study of cognitive development. Merrill-Palmer Quarterly of Behavior and Development, 9(4), 245-252.

Frank, G., Plunkett, S. W., & Otten, M. P. (2010). Perceived parenting, self-esteem, and general self-efficacy of Iranian American adolescents. Journal of Child & Family Studies, 19, 738-746.

Hammer C. S., Hoff, E., Uchikosh1, Y., Gillanders, C., Castro, D., & Sandilos, L. E. (2014). The language literacy development of young dual language learners: A critical review. Early Child Research Quarterly, 29(4), 715-733.

Heckman, J. J., Moon, S. H., Pinto, R., Savelyev, P. A., & Yavitz, A. (2010). The rate of return to the HighScope Perry Preschool Program. Journal of public Economics, 94(1-2), 114-128.

Heckman, J. J. (2006). Skill formation and the economics of investing in disadvantaged children. Science, 312(5782), 1900-1902.

Hines, J. M. (2017). An Overview of Head Start Program Studies. Journal of Instructional Pedagogies, 18.

Hoff, E. (2018). Bilingual development in children of immigrant families. Child Development Perspectives, 12(2), 80-86.

Imai, M., Li, L., Haryu, E., Hirsh-Pasek, K., Golinkoff, R. M., & Shigematsu, J. (2008). Novel noun and verb learning in Chinese, English, and Japanese children: Universality and language-specificity in novel noun and verb learning. Child Development, 79, 979-1000.

Imuta, K., Henry, J. D., Slaughter, V., Selcuk, B., & Ruffman, T. (2016). Theory of mind and prosocial behavior in childhood: A meta-analytic review. Developmental Psychology, 52(8), 1192–1205. https://doi.org/10.1037/dev0000140

John-Steiner, V., & Mahn, H. (1996). Sociocultural approaches to learning and development: A Vygotskian framework. Educational psychologist, 31(3-4), 191-206.

Kaushanskaya, M., Gross, M., & Buac, M. (2014). Effects of classroom bilingualism on task-shifting, verbal memory, and word learning in children. Developmental Science, 17(4), 564-583.

Kaushanskaya, M., & Marian, V. (2009). Bilingualism Reduces Native-Language Interference During Novel-Word Learning. Journal of Experimental Psychology. Learning, Memory, and Cognition, 35(3), 829–835. https://doi.org/10.1037/a0015275

Khalfaoui, A., García-Carrión, R., & Villardón-Gallego, L. (2021). A systematic review of the literature on aspects affecting positive classroom climate in multicultural early childhood education. Early Childhood Education Journal, 49(1), 71-81.

Kozulin, A. (1990). The concept of regression and Vygotskian developmental theory. Developmental review, 10(2), 218-238.

Love, J. M., Kisker, E. E., Ross, C., Raikes, H., Constantine, J., Boller, K., ... & Vogel, C. (2005). The effectiveness of early head start for 3-year-old children and their parents: Lessons for policy and programs. Developmental psychology, 41(6), 885.

Matusov, E. (2015). Comprehension: A dialogic authorial approach. Culture & Psychology, 21(3), 392-416.

McAlister, A. R., & Peterson, C. C. (2007). A longitudinal study of siblings and theory of mind development. Cognitive Development, 22, 258-270.

Meinhardt‐Injac, B., Daum, M. M., & Meinhardt, G. (2020). Theory of mind development from adolescence to adulthood: Testing the two‐component model. British Journal of Developmental Psychology, 38(2), 289-303.

Meloy, B., Gardner, M., & Darling-Hammond, L. (2019). Untangling the evidence on preschool effectiveness. Learning Policy Institute, Palo Alto.

Meyers-Sutton, C. (2005). Multiple voices: An introduction ot bilingualism. Malden, MA: Blackwell Publishers.

Miller, R. (2011). Vygotsky in perspective. Cambridge university press.

National Association for the Education of Young Children. (2025). The 10 NAEYC program standards. Retrieved from http://families.naeyc.org/accredited-article/10-naeyc-program-standards.

Newman, S., & Latifi, A. (2021). Vygotsky, education, and teacher education. Journal of Education for Teaching, 47(1), 4-17.

Perner, J., Ruffman, T., & Leekam, S. R. (1994). Theory of mind is contagious: You catch from your sibs. Child Development, 65, 1228-1238.

Place, S., & Hoff, E. (2016). Effects and non-effects of input in bilingual environments on dual language skills in 2 1/2-year-olds. Bilingualism: Language and Cognition, 19, 1023–1041.

Poulin-Dubois, D. (2020). Theory of mind development: State of the science and future directions. Progress in Brain Research, 254, 141-166.

Price-Williams, D.R., Gordon, W., & Ramirez, M. (1969). Skill and conservation: A study of pottery making children. Developmental Psychology, 1, 769.

Rakoczy, H. (2022). Foundations of theory of mind and its development in early childhood. Nature Reviews Psychology, 1(4), 223-235.

Rogoff, B. (1990). Apprenticeship in thinking: Cognitive development in social context. Oxford university press.

Ryan, C. (2013). Language use in the United States: 2011. Retrieved from https://www2.census.gov/library/publications/2013/acs/acs-22/acs-22.pdf

Scott, S., & Palincsar, A. (2013). Sociocultural theory. Education. com, 1-4.

Shabani, K. (2016). Applications of Vygotsky’s sociocultural approach for teachers’ professional development. Cogent education, 3(1), 1252177.

Shahaeian, A., Peterson, C. C., Slaughter, V., & Wellman, H. M. (2011). Culture and the sequence of steps in theory of mind development. Developmental Psychology, 47(5), 1239-1247.

Simon, P., & Nader-Grosbois, N. (2025). Empathy and theory of mind development at preschool age: a one-year cross-lagged panel study. European Journal of Developmental Psychology, 22(4), 433-455.

Slaughter, V. (2015). Theory of mind in infants and young children: A review. Australian Psychologist, 50(3), 169-172.

Stoltz, T., Weger, U., & da Veiga, M. (2024). Consciousness and education: Contributions by Piaget, Vygotsky and Steiner. Frontiers in Psychology, 15, 1411415.

Taber, K. S. (2025). Mediated learning leading development—The social development theory of Lev Vygotsky. In Science education in theory and practice: An introductory guide to learning theory (pp. 275-292). Cham: Springer Nature Switzerland.

Thomas, R. M. (1979). Comparing theories of child development. Santa Barbara, CA: Wadsworth. Berk, L. E. (2007). Development through the life span (4th ed.). Boston: Allyn and Bacon.

Topçiu, M., & Myftiu, J. (2015). Vygotsky theory on social interaction and its influence on the development of pre-school children. European Journal of Social Sciences Education and Research, 2(3), 172-179.

United States Department of Health and Human Services. (2015). Head Start program facts fiscal year 2013. Retrieved from http://eclkc.ohs.acf.hhs.gov/hslc/data/factsheets/docs/hs-program-fact-sheet-2013.pdf

Vasileva, O., & Balyasnikova, N. (2019). (Re) introducing Vygotsky’s thought: From historical overview to contemporary psychology. Frontiers in psychology, 10, 1515.

Von Suchodoletz, A., Lee, D. S., Henry, J., Tamang, S., Premachandra, B., & Yoshikawa, H. (2023). Early childhood education and care quality and associations with child outcomes: A meta-analysis. PLoS One, 18(5), e0285985.

Vygotsky, L. S. (1978). Socio-cultural theory. Mind in society.

Wang, V., Melnick, H., Leung-GagnĂ, M., Parker, S., & Wechsler, M. (2025). California's Universal Prekindergarten Implementation Progress, 2023-24. Learning Policy Institute.

Wellman, H. M. (2017). The development of theory of mind: Historical reflections. Child Development Perspectives, 11(3), 207-214.

Wellman, H. M. (2018). Theory of mind: The state of the art. European Journal of Developmental Psychology, 15(6), 728-755.

Wellman, H.M., Cross, D., & Watson, J. (2001). Meta-analysis of theory of mind development: The truth about false belief. Child Development, 72(3), 655-684.

Wellman, H. M., Fang, F., Liu, D., Zhu, L, & Liu, L. (2006). Scaling theory of mind understandings in Chinese children. Psychological Science, 17, 1075-1081.

Wertsch, J. V., & Sohmer, R. (1995). Vygotsky on learning and development. Human Development, 38(6), 332-337.

Welsh, J. A., Bierman, K. L., Nix, R. L., & Heinrichs, B. N. (2020). Sustained effects of a school readiness intervention: 5th grade outcomes of the Head Start REDI program. Early Childhood Research Quarterly, 53, 151-160.

Whitaker, A. A., Burchinal, M., Jenkins, J. M., Bailey, D. H., Watts, T. W., Duncan, G. J., ... & Peisner‐Feinberg, E. (2023). Why are preschool programs becoming less effective?. Journal of Policy Analysis and Management.

White House Press Secretary. (2014). Fact Sheet: Invest in US: The White House Summit on Early Childhood Education. Retrieved from https://www.whitehouse.gov/the-press-office/2014/12/10/fact-sheet-invest-us-white-house-summit-early-childhood-education

Wimmer, H., & Perner, J. (1983). Beliefs about beliefs: Representation and constraining function of wrong beliefs in young children’s understanding of deception. Cognition, 13, 103–128.

Yoo, J., & Kaushanskaya, M. (2012). Phonological memory in bilinguals and monolinguals. Memory & Cognition, 40, 1314–1330.

Zachry, A. (2013). 6 Types of Preschool Programs. Retrieved from http://www.parents.com/toddlers-preschoolers/starting -preschool/preparing/types-of-preschool-programs/

Zauche, L. H., Thul, T. A., Mahoney, A. E. D., & Stapel-Wax, J. L. (2016). Influence of language nutrition on children’s language and cognitive development: An integrated review. Early Childhood Research Quarterly, 36, 318-333.

OER Attribution:

“Lifespan Development: A Psychological Perspective, Second Edition” by Martha Lally and Suzanne Valentine-French is licensed under a CC-BY-NC-SA-3.0 / additional written material by Ellen Skinner & Eli Labinger, Portland State University is licensed under a CC-BY-NC-SA-4.0

Lifespan Development by Lumen Learning is licensed under a Creative Commons Attribution 4.0 International License

Video Attributions:

Every kid needs a champion by TED is licensed CC-BY-NC-ND 4.0

Why kids need to learn about gender and sexuality by TED is licensed CC-BY-NC-ND 4.0