Young Infants’ Word Comprehension Given An Unfamiliar Talker or Altered Pronunciations

To understand spoken words, listeners must appropriately interpret co‐occurring talker characteristics and speech sound content. This ability was tested in 6‐ to 14‐months‐olds by measuring their looking to named food and body part images. In the new talker condition (n = 90), pictures were named by an unfamiliar voice; in the mispronunciation condition (n = 98), infants’ mothers “mispronounced” the words (e.g., nazz for nose). Six‐ to 7‐month‐olds fixated target images above chance across conditions, understanding novel talkers, and mothers’ phonologically deviant speech equally. Eleven‐ to 14‐months‐olds also understood new talkers, but performed poorly with mispronounced speech, indicating sensitivity to phonological deviation. Between these ages, performance was mixed. These findings highlight the changing roles of acoustic and phonetic variability in early word comprehension, as infants learn which variations alter meaning.     

The Development of Language Constancy: Attention to Native Versus Nonnative Accents

The time frame for infants' acquisition of language constancy was probed, using the phonetic variation in a rarely heard accent (South African English) or a frequently heard accent (American English). A total of 156 Australian infants were tested. Six‐month‐olds looked longer to Australian English than less commonly heard South African accent, but at 9 months, showed similar looking times. With the more frequently heard American accent, 3‐month‐olds looked longer to Australian and American English, whereas 6‐month‐olds looked equally. Together these results imply that in the 1st year, differential attention to native versus nonnative accents decreases as infants develop a sense of language constancy for the common native language. However, experience with the nonnative accent can expedite this process.     

Training Basic Visual Attention Leads to Changes in Responsiveness to Social‐Communicative Cues in 9‐Month‐Olds

This study investigated transfer effects of gaze‐interactive attention training to more complex social and cognitive skills in infancy. Seventy 9‐month‐olds were assigned to a training group (n = 35) or an active control group (n = 35). Before, after, and at 6‐week follow‐up both groups completed an assessment battery assessing transfer to nontrained aspects of attention control, including table top tasks assessing social attention in seminaturalistic contexts. Transfer effects were found on nontrained screen‐based tasks but importantly also on a structured observation task assessing the infants’ likelihood to respond to an adult's social‐communication cues. The results causally link basic attention skills and more complex social‐communicative skills and provide a principle for studying causal mechanisms of early development.     

Selective Imitation of In‐Group Over Out‐Group Members in 14‐Month‐Old Infants

Recent research has shown that infants are more likely to engage with in‐group over out‐group members. However, it is not known whether infants' learning is influenced by a model's group membership. This study investigated whether 14‐month‐olds (N = 66) selectively imitate and adopt the preferences of in‐group versus out‐group members. Infants watched an adult tell a story either in their native language (in‐group) or a foreign language (out‐group). The adult then demonstrated a novel action (imitation task) and chose 1 of 2 objects (preference task). Infants did not show selectivity in the preference task, but they imitated the in‐group model more faithfully than the out‐group model. This suggests that cultural learning is beginning to be truly cultural by 14 months of age.     

Verbal Positional Memory in 7‐Month‐Olds

Verbal memory is a fundamental prerequisite for language learning. This study investigated 7‐month‐olds' (N = 62) ability to remember the identity and order of elements in a multisyllabic word. The results indicate that infants detect changes in the order of edge syllables, or the identity of the middle syllables, but fail to encode the order of middle syllables. This suggests that the representational format of multisyllabic words is determined by core mnemonic biases, which favor accurate encoding of edges and limits the encoding of temporal order for internal segments. The studies support accounts proposing that content and order are encoded separately; in addition, the data show that this dissociation occurs early in development.     

Limited Fine Motor and Grasping Skills in 6‐Month‐Old Infants at High Risk for Autism

Atypical motor behaviors are common among children with autism spectrum disorders (ASD). However, little is known about onset and functional implications of differences in early motor development among infants later diagnosed with ASD. Two prospective experiments were conducted to investigate motor skills among 6‐month‐olds at increased risk (high risk) for ASD (N₁ = 129; N₂ = 46). Infants were assessed using the Mullen Scales of Early Learning (MSEL) and during toy play. Across both experiments, high‐risk infants exhibited less mature object manipulation in a highly structured (MSEL) context and reduced grasping activity in an unstructured (free‐play) context than infants with no family history of ASD. Longitudinal assessments suggest that between 6 and 10 months, grasping activity increases in high‐risk infants.     

2.5‐Year‐Olds Express Suspense When Others Approach Reality With False Expectations

The study investigated if 2.5‐year‐olds are susceptible to suspense and express tension when others' false expectations are about to be disappointed. In two experiments (N = 32 each), children showed more tension when a protagonist approached a box with a false belief about its content than when she was ignorant. In Experiment 2, children also expressed more tension when the protagonist's belief was false than when it was true. The findings reveal that toddlers affectively anticipate the “rude awakening” of an agent who is about to discover unexpected reality. They thus not only understand false beliefs per se but also grasp the affective implications of being mistaken. The results are discussed with recourse to current theories about early understanding of false beliefs.     

Visual Short‐Term Memory for Complex Objects in 6‐ and 8‐Month‐Old Infants

Infants' visual short‐term memory (VSTM) for simple objects undergoes dramatic development: Six‐month‐old infants can store in VSTM information about only a simple object presented in isolation, whereas 8‐month‐old infants can store information about simple objects presented in multiple‐item arrays. This study extended this work to examine the development of infants' VSTM for complex objects during this same period (N = 105). Using the simultaneous streams change detection paradigm, Experiment 1 confirmed the previous developmental trajectory between 6 and 8 months. Experiment 2 showed that doubling the exposure time did not enhance 6‐month‐old infants' change detection, demonstrating that the developmental change is not due to encoding speed. Thus, VSTM for simple and complex objects appears to follow the same developmental trajectory.     

Enhancing the Executive Functions of 3‐Year‐Olds in the Dimensional Change Card Sort Task

Executive functions enable flexible thinking, something young children are notoriously bad at. For instance, in the dimensional change card sort (DCCS) task, 3‐year‐olds can sort cards by one dimension (shape), but continue to sort by this dimension when asked to switch (to color). This study tests a prediction of a dynamic neural field model that prior experience with the postswitch dimension can enhance 3‐year‐olds' performance in the DCCS. In Experiment 1A, a matching game was used to preexpose 3‐year‐olds (n = 36) to color. This facilitated switching from sorting by shape to color. In 3 , 3‐year‐olds (n = 18) were preexposed to shape. This did not facilitate switching from sorting by color to shape. The model was used to explain this asymmetry.     

From Flexibility to Constraint: The Contrastive Use of Lexical Tone in Early Word Learning

Infants must develop both flexibility and constraint in their interpretation of acceptable word forms. The current experiments examined the development of infants' lexical interpretation of non‐native variations in pitch contour. Fourteen‐, 17‐, and 19‐month‐olds (Experiments 1 and 2, N = 72) heard labels for two novel objects; labels contained the same syllable produced with distinct pitch contours (Mandarin lexical tones). The youngest infants learned the label–object mappings, but the older groups did not, despite being able to discriminate pitch differences in an object‐free task (Experiment 3, N = 14). Results indicate that 14‐month‐olds remain flexible regarding what sounds make meaningful distinctions between words. By 17–19 months, experience with a nontonal native language constrains infants' interpretation of lexical tone.     

Infants Rely More on Gaze Cues From Own‐Race Than Other‐Race Adults for Learning Under Uncertainty

Differential experience leads infants to have perceptual processing advantages for own‐ over other‐race faces, but whether this experience has downstream consequences is unknown. Three experiments examined whether 7‐month‐olds (range = 5.9–8.5 months; N = 96) use gaze from own‐ versus other‐race adults to anticipate events. When gaze predicted an event's occurrence with 100% reliability, 7‐month‐olds followed both adults equally; with 25% (chance) reliability, neither was followed. However, with 50% (uncertain) reliability, infants followed own‐ over other‐race gaze. Differential face race experience may thus affect how infants use social cues from own‐ versus other‐race adults for learning. Such findings suggest that infants integrate online statistical reliability information with prior knowledge of own versus other race to guide social interaction and learning.     

Mental Spatial Transformations in 14‐ and 16‐Month‐Old Infants: Effects of Action and Observational Experience

Infants' ability to mentally track the orientation of an object during a hidden rotation was investigated (N = 28 in each experiment). A toy on a turntable was fully covered and then rotated 90°. When revealed, the toy had turned with the turntable (probable event), remained at its starting orientation (improbable event in Experiment 1), or turned to the opposite side (improbable event in Experiment 2). Results demonstrated a developmental progression between 14 and 16 months of age in infants' sensitivity to spatial object relations and their ability to track the orientation of an object during hidden rotation. Experiment 3 showed that 14‐month‐olds' performance improved with hands‐on training, highlighting the role of action experience in cognitive development.     

Accent,Language, and Race: 4–6‐Year‐Old Children's Inferences Differ by Speaker Cue

Three experiments examined 4‐ to 6‐year‐olds' use of potential cues to geographic background. In Experiment 1 (N = 72), 4‐ to 5‐year‐olds used a speaker's foreign accent to infer that they currently live far away, but 6‐year‐olds did not. In Experiment 2 (N = 72), children at all ages used accent to infer where a speaker was born. In both experiments, race played some role in children's geographic inferences. Finally, in Experiment 3 (N = 48), 6‐year‐olds used language to infer both where a speaker was born and where they currently live. These findings reveal critical differences across development in the ways that speaker characteristics are used as inferential cues to a speaker's geographic location and history.     

Flexibility in Bilingual Infants' Word Learning

The present experiments tested bilingual infants' developmental narrowing for the interpretation of sounds that form words. These studies addressed how language specialization proceeds when the environment provides varied and divergent input. Experiment 1 (N = 32) demonstrated that bilingual 14‐ and 19‐month‐olds learned a pair of object labels consisting of the same syllable produced with distinct pitch contours (rising and falling). Infants' native languages did not use pitch contour to differentiate words. In Experiment 2 (N = 16), 22‐month‐old bilinguals failed to learn the labels. These results conflict with the developmental trajectory of monolinguals, who fail to learn pitch contour contrasts as labels at 17–19 months (Hay, Graf Estes, Wang, & Saffran, 2015). Bilingual infants exhibited a prolonged period of flexibility in their interpretation of potential word forms.     

Infants Perceive Three‐Dimensional Illusory Contours as Occluding Surfaces

The study assessed the contribution of stereoscopic depth cues to infants' perception of a Kanizsa rectangle as a surface that temporarily occludes a moving object. In Experiment 1, the Kanizsa figure was shifted into the foreground by enriching it with stereoscopic depth information. According to the results, perception of a three‐dimensional Kanizsa figure as an occluding surface emerges between 5 (n = 16) and 7 (n = 16) months of age. Experiment 2 demonstrated that 7‐month‐old (n = 16) infants performed similarly to the 7‐month‐olds who participated in Experiment 1 if the moving object was shifted into the background. These findings suggest that 7‐month‐old infants respond to stereoscopic depth cues and that they exploit it to perceive subjective contours as occluders.     

Being Mimicked Increases Prosocial Behavior in 18‐Month‐Old Infants

Most previous research on imitation in infancy has focused on infants' learning of instrumental actions on objects. This study focused instead on the more social side of imitation, testing whether being mimicked increases prosocial behavior in infants, as it does in adults (van Baaren, Holland, Kawakami, & van Knippenberg, 2004). Eighteen‐month‐old infants (N = 48) were either mimicked or not by an experimenter; then either that experimenter or a different adult needed help. Infants who had previously been mimicked were significantly more likely to help both adults than infants who had not been mimicked. Thus, even in infancy, mimicry has positive social consequences: It promotes a general prosocial orientation toward others.     

Realizing Relevance: The Influence of Domain‐Specific Information on Generation of New Knowledge Through Integration in 4‐ to 8‐Year‐Old Children

In accumulating knowledge, direct modes of learning are complemented by productive processes, including self‐generation based on integration of separate episodes. Effects of the number of potentially relevant episodes on integration were examined in 4‐ to 8‐year‐olds (N = 121; racially/ethnically heterogeneous sample, English speakers, from large metropolitan area). Information was presented along with unrelated or related episodes; the latter challenged children to identify the relevant subset of episodes for integration. In Experiment 1, 4‐ and 6‐year‐olds integrated in the unrelated context. Six‐year‐olds also succeeded in the related context in forced‐choice testing. In Experiment 2, 8‐year‐olds succeeded in open‐ended and forced‐choice testing. Results illustrate a developmental progression in productive extension of knowledge due in part to age‐related increases in identification of relevant information.     

Young Word Learners’ Interpretations of Words and Symbolic Gestures Within the Context of Ambiguous Reference

Early in development, many word‐learning phenomena generalize to symbolic gestures. The current study explored whether children avoid lexical overlap in the gestural modality, as they do in the verbal modality, within the context of ambiguous reference. Eighteen‐month‐olds’ interpretations of words and symbolic gestures in a symbol‐disambiguation task (Experiment 1) and a symbol‐learning task (Experiment 2) were investigated. In Experiment 1 (N = 32), children avoided verbal lexical overlap, mapping novel words to unnamed objects; children failed to display this pattern with symbolic gestures. In Experiment 2 (N = 32), 18‐month‐olds mapped both novel words and novel symbolic gestures onto their referents. Implications of these findings for the specialized nature of word learning and the development of lexical overlap avoidance are discussed.     

Parent Praise to 1‐ to 3‐Year‐Olds Predicts Children's Motivational Frameworks 5 Years Later

In laboratory studies, praising children's effort encourages them to adopt incremental motivational frameworks—they believe ability is malleable, attribute success to hard work, enjoy challenges, and generate strategies for improvement. In contrast, praising children's inherent abilities encourages them to adopt fixed‐ability frameworks. Does the praise parents spontaneously give children at home show the same effects? Although parents' early praise of inherent characteristics was not associated with children's later fixed‐ability frameworks, parents' praise of children's effort at 14–38 months (N = 53) did predict incremental frameworks at 7–8 years, suggesting that causal mechanisms identified in experimental work may be operating in home environments.     

“Everything Happens for a Reason”: Children's Beliefs About Purpose in Life Events

Do children believe that “everything happens for a reason?” That is, do children endorse purpose‐based, teleological explanations for significant life events, as they do for social behavior, artifacts, biological properties, and natural kinds? Across three experiments, 5‐ to 7‐year‐olds (N = 80), 8‐ to 10‐year‐olds (N = 72), and adults (N = 91) chose between teleological and nonteleological accounts of significant life events and judged how helpful those accounts were for understanding an event's cause. Five‐ to 7‐year‐olds favored teleological explanations, but this preference diminished with age. Five‐ to 7‐year‐olds and 8‐ to 10‐year‐olds also found teleological explanations more helpful than did adults. Perceiving purpose in life events may therefore have roots in childhood, potentially reflecting a more general sensitivity to purpose in the social and natural worlds.