Four experiments compared 4-year-olds' understanding of pretense to that of 3-year-olds or adults. When shown pictured items, 4-year-olds understood that only animates pretend, but 3-year-olds sometimes claimed that inanimates pretend. When shown actual items, even 4-year-olds sometimes claimed that inanimates pretend, especially when adults…

Three experiments investigated children's understanding of inference as a knowledge source. Most 4- to 6-year-olds did not rate a puppet as more certain of a toy's color after the puppet looked at the toy or inferred its color than they did after the puppet guessed the color. Most 8- and 9-year-olds distinguished inference and looking from…

Two studies involving approximately 200 children aged 4 to 12 years show the expected increases in the level of cognitive competencies but show that these increases are not universal. Large inter- and intraindividual differences are found for various types of memory tasks as well as for different domains of scholastic achievement. (SLD)

Three experiments examined whether preschoolers viewed outcomes of familiar causes of illness as definite or probabilistic. Findings indicated that children judged that a common cause would affect all group members the same, and believed they could definitely predict illness outcomes in a single case, contrasting with adults' variable and…

Examined the degree of specificity encoded in early lexical representations by presenting 18- to 23-month-olds with object labels either correctly or incorrectly pronounced and analyzing children's eye movement. Found that children recognized the spoken words in both conditions but recognition was poorer when words were mispronounced, with effects…

Three experiments investigated use of vitalistic explanations for biological phenomena by 5- and 10-year-olds and by adults. Results replicated the original Japanese finding of vitalistic thinking among English-speaking 5-year-olds, identified the more active component of vitalism as a belief in the transfer of energy during biological processes,…

Examined 3- to 5-year olds' justifications for conformity to physical laws and social rules. Found that children's justifications for social rule conformity involved consequences and permission/obligation, and for physical laws involved physical limitations or impossibility. Older preschoolers, but not 3-year olds, appreciated that social…

Tested the hypothesis that in predicting future behavior of an actor, older children rely on trait inferences, whereas younger children rely on global, evaluative inferences. Found that 9- and 10-year-olds' behavioral predictions were mediated solely by trait ratings, whereas 5- and 6-year-olds' predictions were mediated by evaluative ratings. The…

Two studies addressed whether preschoolers consider speakers' knowledge states when establishing initial word-referent links. Children showed better learning from a speaker knowledgeable of novel words' referents than from an ignorant speaker. Four-year-olds, but not 3-year-olds, learned words better when speaker said the object was made by…

Tested role of event plausibility and script-relevant knowledge in events suggestively planted in memory of 5- to 7-year olds and 9- to 12-year olds. Found that the majority did not remember either false event. Significantly more children recalled the plausible but not the implausible false event; only one recalled the implausible but not…

Examined role of spontaneous gesture in 2- to 4-year-olds' counting and assessment of counting accuracy. Found that correspondence of children's speech and gesture varied systematically across age. Children adhered to one-to-one correspondence principle in gesture prior to speech. Counting accuracy related to correspondence of speech and gesture,…

Conducted meta-analysis to examine empirical inconsistencies and theoretical controversies concerning false-belief tasks and understanding about mental states. Found that a combined model including age, country of origin, and four task factors accounted for 55 percent of the variance in false-belief performance. Findings are consistent with…

Examined in 2 studies 2- to 4-year-olds' learning of novel words and novel facts and extension of the words and facts to additional exemplars. Found that children extended the novel word to more category members than they extended the novel fact. By age 2, children observe extendibility of novel count nouns but are uncertain about extendibility of…

Examined third- and seventh-graders' and college students' thinking regarding different types of disagreements. Found that participants' thinking was constrained by the realm and form of the disagreement. At all ages, participants judged some disagreements acceptable and others unacceptable, described disagreements based on different attributes,…

Age-related changes in representational flexibility are a characteristic feature of declarative memory development. The authors suggest that a qualitative shift in the nature of infants' memory representations accounts for increasing memory flexibility with age. We will argue that a comprehensive theory of declarative memory development must (1)…