The Early Social Cognition Inventory (ESCI): An examination of its psychometric properties from birth to 47 months.

Social cognition refers to a broad range of cognitive processes and skills that allow individuals to interact with and understand others, including a variety of skills from infancy through preschool and beyond, e.g., joint attention, imitation, and belief understanding. However, no measures examine socio-cognitive development from birth through preschool. Current test batteries and parent-report measures focus either on infancy, or toddlerhood through preschool (and beyond). We report six studies in which we developed and tested a new 21-item parent-report measure of social cognition targeting 0-47 months: the Early Social Cognition Inventory (ESCI). Study 1 (N = 295) revealed the ESCI has excellent internal reliability, and a two-factor structure capturing social cognition and age. Study 2 (N = 605) also showed excellent internal reliability and confirmed the two-factor structure. Study 3 (N = 84) found a medium correlation between the ESCI and a researcher-administered social cognition task battery. Study 4 (N = 46) found strong 1-month test-retest reliability. Study 5 found longitudinal stability (6 months: N = 140; 12 months: N = 39), and inter-observer reliability between parents (N = 36) was good, and children's scores increased significantly over 6 and 12 months. Study 6 showed the ESCI was internally reliable within countries (Australia, Canada, United Kingdom, United States, Trinidad and Tobago); parent ethnicity; parent education; and age groups from 4-39 months. ESCI scores positively correlated with household income (UK); children with siblings had higher scores; and Australian parents reported lower scores than American, British, and Canadian parents.

The Early Humor Survey (EHS): A reliable parent-report measure of humor development for 1- to 47-month-olds.

We created a 20-item parent-report measure of humor development from 1 to 47 months: the Early Humor Survey (EHS). We developed the EHS with Study 1 (N = 219) using exploratory factor analysis, demonstrating the EHS works with 1- to 47-month-olds with excellent reliability and a strong correlation with age, showing its developmental trajectory. We replicated the EHS with Study 2 (N = 587), revealing a one-factor structure, showing excellent reliability, and replicating a strong correlation with age. Study 3 (N = 84) found the EHS correlated with a humor experiment, however it no longer correlated once age was accounted for, suggesting low convergent validity. Subsamples of parents from Studies 2 and 3 showed excellent inter-observer reliability between both parents, and good longitudinal stability after 6 months. Combining participants from all studies, we found the EHS is reliable across countries (Australia, United Kingdom, United States), parent education levels, and children's age groups. We charted expected humor development by age (in months), and the expected proportion of children who would appreciate each humor type by age (in months). Finally, we found no demographic differences (e.g., country: Australia, Canada, United Kingdom, United States; parents' education) in humor when pooling all data. The EHS is a valuable tool that will allow researchers to understand how humor: (1) emerges; and (2) affects other aspects of life, e.g., making friends, coping with stress, and creativity. The EHS is helpful for parents, early years educators, and children's media, as it systematically charts early humor development.

Preschoolers understand and generate pretend actions using object substitution.

Pretend play is often considered to be an imaginative or creative activity. Yet past experimental research has focused on whether children imitate pretense, follow instructions to pretend, or understand others' pretense. Thus, we cannot be sure that children's pretense is in fact novel or whether children simply copy or follow others' instructions. This is the first experiment to show that preschoolers generate their own novel object substitutions. In Study 1, 45 3- and 4-year-olds saw an experimenter use one object as another accompanied by pretend or trying cues. Children differentiated between the experimenter's intentions by imitating the actions accompanied by pretend cues and correcting the actions accompanied by trying cues. In addition, when the experimenter made her intentions to pretend or try explicit, children produced significantly more novel object substitutions not modeled or verbally requested by the experimenter within a pretend context than within a trying context. Study 2 replicated these findings with 34 3-year-olds using a repeated-measures design. However, it found no relationship between children's copying or generation of object substitutions and divergent thinking, inhibitory control, or pretense during free play.

Humor and preschoolers' trust: Sensitivity to changing intentions.

This research demonstrates that preschoolers (a) avoid trusting informants with humorous intentions when learning novel information and (b) flexibly consider current intentions rather than initial intentions when determining who to trust. In Study 1 (N=61), 3- and 4-year-olds based their trust on intentions or intentional cues alone, trusting a sincere informant over a joker, even when no prior accuracy or inaccuracy was displayed. In Study 2 (N=32), 3- and 4-year-olds flexibly based their trust on the informants' current intentions or intentional cues rather than their initial ones. Children trusted a sincere informant, who originally joked, over a joker, who was originally sincere. In Study 3 (N=89), 3-, 4-, and 5-year-olds tracked changing intentions, and not just intentional cues, in determining who to trust. Children trusted an informant who joked during training trials but was sincere during test trials over an informant who was ignorant during training trials and was sincere during test trials. However, if the ignorant informant became knowledgeable and the joker continued to joke, the pattern reversed. This is the first study to show that preschoolers consider intentions to joke when learning information. This is also the first study to show that preschoolers do not see trust as stable but rather see it as a function of changing intentions.

Two-Year-Olds Distinguish Pretending and Joking.

Although children understand intentions to joke and pretend by 2 or 3 years, it is unclear whether they distinguish these intentional acts. Using a normativity paradigm, this study found (N = 72) 2-year-olds protest against jokes more than pretending, suggesting, for the first time, they distinguish these acts. Furthermore, toddlers protested more generally after pretend than literal or joke contexts but only if intentional cues were used. Additionally, children objected more to joking than pretending after pretend and literal contexts but not after joke contexts. Thus, toddlers distinguish the intentional nature of pretending and joking. Furthermore, a pretend intentional context establishes specific rules to be followed, whereas a joke intentional context allows an open space to perform various types of acts.

One-Year-Olds Think Creatively, Just Like Their Parents.

Creativity is an essential human ability, allowing adaptation and survival. Twenty-nine 1-year-olds and their parents were tested on divergent thinking (DT), a measure of creative potential counting how many ideas one can generate. Toddlers' and parents' DT was moderately to highly correlated. Toddlers showed a wide range of DT scores, which were reliable on retesting. This is the first study to show children think divergently as early as 1 year. This research also suggests 1-year-olds' DT is related to parents', opening up future research into whether this relationship is due to genetics and/or social learning at its emergence. Understanding DT at its emergence could allow for interventions while neurological development is most plastic, which could improve DT across the life span.

Liar, liar, working memory on fire: Investigating the role of working memory in childhood verbal deception.

The aim of the current study was to investigate the role of working memory in verbal deception in children. We presented 6- and 7-year-olds with a temptation resistance paradigm; they played a trivia game and were then given an opportunity to peek at the final answers on the back of a card. Measures of both verbal and visuospatial working memory were included. The good liars performed better on the verbal working memory test in both processing and recall compared with the bad liars. However, there was no difference in visuospatial working scores between good liars and bad liars. This pattern suggests that verbal working memory plays a role in processing and manipulating the multiple pieces of information involved in lie-telling.

Acoustic differences between humorous and sincere communicative intentions.

Previous studies indicate that the acoustic features of speech discriminate between positive and negative communicative intentions, such as approval and prohibition. Two studies investigated whether acoustic features of speech can discriminate between two positive communicative intentions: humour and sweet-sincerity, where sweet-sincerity involved being sincere in a positive, warm-hearted way. In Study 1, 22 mothers read a book containing humorous, sweet-sincere, and neutral-sincere images to their 19- to 24-month-olds. In Study 2, 41 mothers read a book containing humorous or sweet-sincere sentences and images to their 18- to 24-month-olds. Mothers used a higher mean F0 to communicate visual humour as compared to visual sincerity. Mothers used greater F0 mean, range, and standard deviation; greater intensity mean, range, and standard deviation; and a slower speech rate to communicate verbal humour as compared to verbal sweet-sincerity. Mothers used a rising linear contour to communicate verbal humour, but used no specific contour to express verbal sweet-sincerity. We conclude that speakers provide acoustic cues enabling listeners to distinguish between positive communicative intentions.

Early humour production.

The current studies explored early humour as a complex socio-cognitive phenomenon by examining 2- and 3-year-olds' humour production with their parents. We examined whether children produced novel humour, whether they cued their humour, and the types of humour produced. Forty-seven parents were interviewed, and videotaped joking with their children. Other parents (N= 113) completed a survey. Parents reported children copy jokes during the first year of life, and produce novel jokes from 2 years. In play sessions, 3-year-olds produced mostly novel humorous acts; 2-year-olds produced novel and copied humorous acts equally frequently. Parents reported children smile, laugh, and look for a reaction when joking. In play sessions, 2- and 3-year-olds produced these behaviours more when producing humorous versus non-humorous acts. In both parent reports and play sessions, they produced novel object-based (e.g., underwear on head) and conceptual humour (e.g., 'pig says moo') and used wrong labels humorously (e.g., calling a cat a dog). Thus, parent report and child behaviour both confirm that young children produce novel humorous acts, and share their humour by smiling, laughing, and looking for a reaction.

Learning foreign labels from a foreign speaker: the role of (limited) exposure to a second language.

Three- and four-year-olds (N = 144) were introduced to novel labels by an English speaker and a foreign speaker (of Nordish, a made-up language), and were asked to endorse one of the speaker's labels. Monolingual English-speaking children were compared to bilingual children and English-speaking children who were regularly exposed to a language other than English. All children tended to endorse the English speaker's labels when asked 'What do you call this?', but when asked 'What do you call this in Nordish?', children with exposure to a second language were more likely to endorse the foreign label than monolingual and bilingual children. The findings suggest that, at this age, exposure to, but not necessarily immersion in, more than one language may promote the ability to learn foreign words from a foreign speaker.

Preschoolers joke with jokers, but correct foreigners.

Thirty- and 36-month-old English speakers' (N = 106) ability to produce jokes, distinguish between humorous and sincere intentions, and distinguish between English- and foreign-language speakers, was examined in two tasks. In the Giving task, an experimenter requested one of two familiar objects, and a confederate always gave her the wrong object. In the Naming task, the confederate mislabeled familiar objects. In the English-speaking conditions, the confederate laughed after doing the wrong thing (English-Humor) or said, 'There!' (English-Sincere). In the Foreign conditions, the French- or Italian-speaking confederate laughed (Foreign-Humor) or said, 'D'accord!' or 'Va bene!' (Foreign-Sincere). When preschoolers were subsequently requested to give and name the same objects and a new set of familiar objects they were significantly more likely to imitate and 'do the wrong thing' in the Humor versus Sincere, and in the English versus Foreign conditions.

Language Signaling High Proportions and Generics Lead to Generalizing, but Not Essentializing, for Novel Social Kinds.

Generics (e.g., "Dogs bark") are thought by many to lead to essentializing: to assuming that members of the same category share an internal property that causally grounds shared behaviors and traits, even without evidence of such a shared property. Similarly, generics are thought to increase generalizing, that is, attributing properties to other members of the same group given evidence that some members of the group have the property. However, it is not clear from past research what underlies the capacity of generic language to increase essentializing and generalizing. Is it specific to generics, or are there broader mechanisms at work, such as the fact that generics are terms that signal high proportions? Study 1 (100 5-6 year-olds, 140 adults) found that neither generics, nor high-proportion quantifiers ("most," "many") elicited essentializing about a novel social kind (Zarpies). However, both generics and high-proportion quantifiers led adults and, to a lesser extent, children, to generalize, with high-proportion quantifiers doing so more than generics for adults. Specifics ("this") did not protect against either essentializing or generalizing when compared to the quantifier "some." Study 2 (100 5-6 year-olds, 112 adults) found that neither generics nor visual imagery signaling high proportions led to essentializing. While generics increased generalizing compared to specifics and visual imagery signaling both low and high proportions for adults, there was no difference in generalizing for children. Our findings suggest high-proportion quantifiers, including generics, lead adults, and to some extent children, to generalize, but not essentialize, about novel social kinds.

Humor, abstraction, and disbelief.

We investigated humor as a context for learning about abstraction and disbelief. More specifically, we investigated how parents support humor understanding during book sharing with their toddlers. In Study 1, a corpus analysis revealed that in books aimed at 1-to 2-year-olds, humor is found more often than other forms of doing the wrong thing including mistakes, pretense, lying, false beliefs, and metaphors. In Study 2, 20 parents read a book containing humorous and non-humorous pages to their 19-to 26-month-olds. Parents used a significantly higher percentage of high abstraction extra-textual utterances (ETUs) when reading the humorous pages. In Study 3, 41 parents read either a humorous or non-humorous book to their 18-to 24-month-olds. Parents reading the humorous book made significantly more ETUs coded for a specific form of high abstraction: those encouraging disbelief of prior utterances. Sharing humorous books thus increases toddlers' exposure to high abstraction and belief-based language.

Two-year-olds can socially learn to think divergently.

This study aimed to discover whether 2-year-olds can socially learn to think divergently. Two-year-olds (N = 22) who saw an experimenter model a high level of divergent thinking on the Unusual Box Test (modelling 25 different actions, once each) went on to demonstrate a higher level of divergent thinking themselves than (N = 22) children who saw a low level of modelling (five different actions, once each), where divergent thinking was measured by the number of different actions children produced that had not been modelled by the experimenter. Additionally, all children in both High and Low Divergence conditions had higher divergent thinking than imitation scores, where imitation involved copying the experimenter's previous actions. This is the first experiment to show that 2-year-olds' divergent thinking can be increased, and that 2-year-olds do so by socially learning to think more divergently. Statement of contribution What is already known on this subject Recent research found that children as young as 1 year can think divergently, and that this is influenced by parents' own divergent thinking. What does this study add? This paper is important as it provides the first method to increase divergent thinking in toddlers. It also shows that social learning can directly affect individual learning processes, which suggests current theories of social and individual learning should be revised to be more iterative.

Parents Produce Explicit Cues That Help Toddlers Distinguish Joking and Pretending.

While separate pieces of research found parents offer toddlers cues to express that they are (1) joking and (2) pretending, and that toddlers and preschoolers understand intentions to (1) joke and (2) pretend, it is not yet clear whether parents and toddlers consider joking and pretending to be distinct concepts. This is important as distinguishing these two forms of non-literal acts could open a gateway to understanding the complexities of the non-literal world, as well as the complexities of intentions in general. Two studies found parents offer explicit cues to help 16- to 24-month-olds distinguish pretending and joking. Across an action play study (n = 25) and a verbal play study (n = 40) parents showed more disbelief and less belief through their actions and language when joking versus pretending. Similarly, toddlers showed less belief through their actions, and older toddlers showed less belief through their language. Toddlers' disbelief could be accounted for by their response to parents' language and actions. Thus, these studies reveal a mechanism by which toddlers learn to distinguish joking and pretending. Parents offer explicit cues to distinguish these intentions, and toddlers use these cues to guide their own behaviors, which in turn allows toddlers to distinguish these intentional contexts.

Individual differences and age-related changes in divergent thinking in toddlers and preschoolers.

Divergent thinking shows the ability to search for new ideas, which is an important factor contributing to innovation and problem solving. Current divergent thinking tests allow researchers to study children's divergent thinking from the age of 3 years on. This article presents the first measure of divergent thinking that can be used with children as young as 2 years. The Unusual Box test is a nonverbal and nonimitative test in which children play individually with a novel toy and novel objects. Divergent thinking is scored as the number of different actions performed. Study 1 shows that the Unusual Box test is a valid measure of divergent thinking as it correlates with standard measures of divergent thinking in 3- and 4-year-olds. Study 2 indicates that the test can be used with 2-year-olds, as it shows high test-retest reliability, demonstrating that 2-year-olds can think divergently. Across both studies, individual differences and age-related changes were found, indicating that some children are better at divergent thinking than others and that children's divergent thinking increases with age. This test will allow researchers to gain insight into the early emergence of divergent thinking.