Lifespan Development. Tara L. Kuther

in stories, especially stories in which characters play tricks to surprise or deceive one another. Children who receive the training improved their performance in subsequent false-belief tasks (Liu, Wellman, Tardif, & Sabbagh, 2008; Milligan, Astington, & Dack, 2007; Slaughter & Perez-Zapata, 2014). Similarly, conversation about deceptive objects (e.g., a pen that looked like a flower) also improves performance on false-belief tasks (Lohmann & Tomasello, 2003).

      Metacognition

      Theory of mind is a precursor to the development of metacognition (Lecce, Demicheli, Zocchi, & Palladino, 2015). Young children know that the mind is where thinking takes place. Between 3 and 5, children come to understand that they can know something that others do not (essential for success on false-belief tasks), that their thoughts cannot be observed, and that there are individual differences in mental states (Pillow, 2008). They begin to understand that someone can think of one thing while doing something else, that a person whose eyes and ears are covered can think, and that thinking is different from talking, touching, and knowing (Flavell et al., 1995). However, young children’s understanding of the mind is far from complete. Three- and four-year-old children do not understand that we think even when we are inactive. They look for visible indicators of thinking—perhaps one reason why teachers of young children refer to “putting on your thinking cap”—and assume their absence indicates the absence of thought. It is not until middle childhood that children understand that the mind is always active (Flavell, 1999). Likewise, preschoolers tend to think of the mind as simply a container for items, but older children tend to see the mind as an active constructor of knowledge that receives, processes, and transforms information (Chandler & Carpendale, 1998).

      Young children show limited knowledge of memory functions, contributing to their poor performance on memory tasks. Four-year-olds recognize that increasing the number of items on a list makes recall more difficult and that longer retention intervals increase the likelihood of forgetting (Pillow, 2008). But they know little about the effectiveness of deliberate memory strategies. For example, whereas 6- and 7-year-olds demonstrated an understanding of the role of deliberate practice in memory and practiced without being prompted, 5-year-olds showed an understanding of deliberate practice and some capacity to practice, but 4-year-olds showed neither of these capabilities (Brinums, Imuta, & Suddendorf, 2018). The advances that take place in information processing during early childhood are summarized in Table 7.3.

Table 7.3

      Thinking in Context 7.3

      1 What are the practical implications of young children’s capacities for attention and memory?

      2 In what ways might brain development account for cognitive changes that we see in early childhood such as increases in information processing capacity and changes in reasoning?

      3 Recall from Chapter 1 that development is influenced by multiple contexts. How might contextual influences—family, neighborhood, sociocultural context, and even cohort or generation—influence aspects of cognitive development, such as autobiographical memory or theory of mind?

      Language Development in Early Childhood

      Toddlers transitioning from infancy to early childhood tend to use telegraphic speech. They learn to use multiple elements of speech, such as plurals, adjectives, and the past tense. Children’s vocabulary and grammar become dramatically more complex during early childhood, enabling them to communicate, but also think, in new ways.

      Vocabulary

      At 2 years of age, the average child knows about 500 words; vocabulary acquisition continues at a rapid pace. The average 3-year-old child has a vocabulary of 900 to 1,000 words. By 6 years of age, most children have a vocabulary of about 14,000 words, which means that the average child learns a new word every 1 to 2 hours, every day (Owens, 2015). How is language learned so quickly? Children continue to use fast mapping (see Chapter 5) as a strategy to enable them to learn the meaning of a new word after hearing it once or twice based on contextual association and understanding (Kucker, McMurray, & Samuelson, 2015). Fast mapping improves with age.

      Children learn words that they hear often, that label things and events that interest them, and that they encounter in contexts that are meaningful to them (Harris et al., 2011). Preschoolers can learn words from watching videos with both human and robot speakers, but they learn more quickly in response to human speakers (Moriguchi, Kanda, Ishiguro, Shimada, & Itakura, 2011), especially when the speaker responds to them, such as through videoconferencing (e.g., Skype) (Roseberry et al., 2014). Children learn best in interactive contexts with parents, teachers, siblings, and peers that entail turn-taking, joint attention, and scaffolding experiences that provide hints to the meaning of new words (MacWhinney, 2015).

      Another strategy that children use to increase their vocabulary is logical extension. When learning a word, children extend it to other objects in the same category. For example, when learning that a dog with spots is called a Dalmatian, a child may refer to a Dalmatian bunny (a white bunny with black spots) or a Dalmatian horse. Children tend to make words their own and apply them to all situations they want to talk about (Behrend, Scofield, & Kleinknecht, 2001). At about age 3, children demonstrate the mutual exclusivity assumption in learning new words: They assume that objects have only one label or name. According to mutual exclusivity, a new word is assumed to be a label for an unfamiliar object, not a synonym or second label for a familiar object (Markman, Wasow, & Hansen, 2003). In one study, young children were shown one familiar object and one unfamiliar object. They were told, “Show me the X,” where X is a nonsense syllable. The children reached for the unfamiliar object, suggesting that they expect new words to label new objects rather than acting as synonyms (Markman & Wachtel, 1988). Similarly, young children use the mutual exclusivity assumption to learn the names of parts of objects, such as the brim of a hat, the cab of a truck, or a bird’s beak (Hansen & Markman, 2009).

      At around 5 years of age, many children can infer the meanings of words given the context. They can quickly understand and apply most words they hear.

      RayArt Graphics / Alamy Stock Photo

      By 5 years of age, many children can quickly understand and apply most words that they hear. If a word is used in context or explained with examples, most 5-year-olds can learn it. Preschoolers learn words by making inferences given the context—and inferential learning is associated with better retention than learning by direct instruction (Zosh, Brinster, & Halberda, 2013). Certain classes of words are challenging for young children. For example, they have difficulty understanding that words that express comparisons—tall and short or high and low—are relative in nature and are used in comparing one object to another. Thus, the context defines their meaning, such that calling an object tall is often meant in relation to another object that is short. Children may erroneously interpret tall as referring to all tall things and therefore miss the relative nature of the term (Ryalls, 2000). Children also have difficulty with words that express relative place and time, such as here, there, now, yesterday, and tomorrow. Despite these errors, children make great advances in vocabulary, learning thousands of words each year.

      Early Grammar

      Young children quickly learn to combine words into sentences in increasingly sophisticated ways that follow the complex rules of grammar (de Villiers & de Villiers, 2014). Three-year-old children tend to use plurals, possessives, and past tense (Park, Yelland, Taffe, & Gray, 2012). They also tend to understand the use of pronouns such as I, you, and we. Similar