Show, give, and point gestures across infancy differentially predict language development

Early gesture use predicts children's language development in South Korea: New evidence supporting the cross-cultural importance of pointing

Research in the U.S. and other Western countries shows that children's early gesture use, which starts prior to verbal communication, is an important predictor of children's later language development. Despite increasing efforts to study gesture use in diverse contexts, most of our knowledge on the role of gesture is largely based on populations of Western countries. In this study, we add to the growing body of international research by examining gesture use by 31 mothers and their 14-month-old infants (12 girls) in South Korea and investigate the gestures used during interaction, and whether early gesture use at 14 months predicts Korean children's later language skills at 36 months. The results showed that in addition to using gestures observed in other cultural contexts, Korean mother-child dyads used culturally specific gesture (i.e., bowing), showing an early sign of socialization that starts with preverbal children. In addition, Korean infants' index-finger pointing, but not showing and giving, predicted their later receptive and expressive vocabulary skills at 36 months, providing additional support for the importance of pointing in early language development.

Infants' use of the index finger for social and non-social purposes during the first two years of life: A cross-cultural study

The emergence of the pointing gesture is a major developmental milestone in human infancy. Pointing fosters preverbal communication and is key for language and theory of mind development. Little is known about its ontogenetic origins and whether its pathway is similar across different cultures. The goal of this study was to examine the theoretical proposal that social pointing is preceded by a non-social use of the index finger and later becomes a social-communicative gesture. Moreover, the study investigated to which extent the emergence of social pointing differs cross-culturally. We assessed non-social index-finger use and social pointing in 647 infants aged 3- to 24 months from 4 different countries (China, Germany, Japan, and Türkiye). Non-social index-finger use and social pointing increased with infants' age, such that social pointing became more dominant than non-social index-finger use with age. Whereas social pointing was reported across countries, its reported frequency differed between cultures with significantly greater social pointing frequency in infants from Türkiye, China, and Germany compared to Japanese infants. Our study supports theoretical proposals of the dominance of non-social index-finger use during early infancy with social pointing becoming more prominent as infants get older. These findings contribute to our understanding of infants' use of their index finger for social and non-social purposes during the first two years of life.

Infants who develop autism show smaller inventories of deictic and symbolic gestures at 12 months of age

Gestures are an important social communication skill that infants and toddlers use to convey their thoughts, ideas, and intentions. Research suggests that early gesture use has important downstream impacts on developmental processes, such as language learning. However, autistic children are more likely to have challenges in their gestural development. The current study expands upon previous literature on the differences in gesture use between young autistic and non-autistic toddlers by collecting data using a parent-report questionnaire called the MCDI-Words and Gestures at three time points, 12, 18, and 24 months of age. Results (N = 467) showed that high-likelihood infants who later met diagnostic criteria for ASD (n = 73 HL-ASD) have attenuated gesture growth from 12 to 24 months for both deictic gestures and symbolic gestures when compared to high-likelihood infants who later did not meet criteria for ASD (n = 249 HL-Neg) and low-likelihood infants who did not meet criteria for ASD (n = 145 LL-Neg). Other social communicative skills, like play behaviors and imitation, were also found to be impacted in young autistic children when compared to their non-autistic peers. Understanding early differences in social communication growth before a formal autism diagnosis can provide important insights for early intervention.

Patterns of attention-sensitive communication contribute to 7-20-month-olds' emerging pragmatic skills

The present study aimed at investigating the ability of 7- to 20-month-old infants to display attention-sensitive communication using either canonical markers of language acquisition (e.g., pointing gestures, canonical babblings) or other signals based on the physical features actually perceived by the mother in everyday interaction (e.g., body movements, mouth sounds). We studied 30 French mother-infant dyads in naturalistic settings. We assessed the infants' attention-sensitive communication through unimodal and cross-modal adjustment, defined as the capacity of infants to address visually inattentive mothers by avoiding visual communication mismatches and/or favoring communication matches through audible-or-contact signals. Unimodal and cross-modal adjustments were tested for specific signals across spontaneous "conditions" of maternal visual attention (attentive/inattentive) from video footage filmed in the home. Both canonical markers of language development and signals belonging to an extended repertoire of communication were used by infants to adjust to their mother's visual attention. Gaze-coordinated signals were overall not significantly better adjusted to maternal attention than non-gaze-coordinated signals, except for specific silent-visual signals at certain ages. Overall, these results indicate that attention-sensitive communication is relevant to the development of early pragmatic skills and that the intentional use of signals may be more reliably approximated by this capacity than by gaze-coordination with signals.

The breadth and specificity of 18-month-old's infant-initiated interactions in naturalistic home settings

Infants actively initiate social interactions aiming to elicit different types of responses from other people. This study aimed to document a variety of communicative interactions initiated by 18-month-old Turkish infants from diverse SES (N = 43) with their caregivers in their natural home settings. The infant-initiated interactions such as use of deictic gestures (e.g., pointing, holdouts), action demonstrations, vocalizations, and non-specific play actions were coded from video recordings and classified into two categories as need-based and non-need-based. Need-based interactions were further classified as a) biological (e.g., feeding); b) socio-emotional (e.g., cuddling), and non-need-based interactions (i.e., communicative intentions) were coded as a) expressive, b) requestive; c) information/help-seeking; d) information-giving. Infant-initiated non-need-based (88%) interactions were more prevalent compared to need-based interactions (12%). Among the non-need-based interactions, 50% aimed at expressing or sharing attention or emotion, 26% aimed at requesting an object or an action, and 12% aimed at seeking information or help. Infant-initiated information-giving events were rare. We further investigated the effects of familial SES and infant sex, finding no effect of either on the number of infant-initiated interactions. These findings suggest that at 18 months, infants actively communicate with their social partners to fulfil their need-based and non-need-based motivations using a wide range of verbal and nonverbal behaviors, regardless of their sex and socio-economic background. This study thoroughly characterizes a wide and detailed range of infant-initiated spontaneous communicative bids in hard-to-access contexts (infants' daily lives at home) and with a traditionally underrepresented non-WEIRD population.

The Role of Gesture in Language Development for Neurotypical Children and Children With or at Increased Likelihood of Autism

For young children, gesture is found to precede and predict language development. However, we are still building a knowledge base about the specific nature of the relationship between gesture and speech. While much of the research on this topic has been conducted with neurotypical children, there is a growing body of work with children who have or are at increased likelihood of autism spectrum disorder (ASD). Here, we summarize the literature on relations between gesture and speech, including the role of child gesture production as well as that of gesture exposure (caregiver gesture). We include literature on both neurotypical children and children with or at likelihood of ASD, highlight the similarities and differences across populations, and offer implications for research as well as early identification and intervention.

Prelinguistic communication complexity predicts expressive language in initial minimally verbal autistic children

BACKGROUND

Prelinguistic communication complexity refers to the use of different communication forms such as eye gaze, gestures and vocalisations and the degree to which these forms are coordinated and how directed to a communication partner. To date, little is known about the relationship between prelinguistic communication complexity and expressive language in minimally verbal autistic children.

AIMS

To test the hypothesis that prelinguistic communication complexity predicts expressive language 12 months later in autistic children and explore whether there are any differences in specific prelinguistic intentional communicative behaviours that are related to later expressive language levels.

METHODS & PROCEDURES

This longitudinal study examined 37 minimally verbal autistic children (29-71 months old). The Communication Complexity Scale (CCS) was used to measure participants' prelinguistic communication behaviours, which were extracted from a semi-structured play interaction at Time 1. The Chinese Communicative Development Inventory (CCDI) was used to examine participants' expressive language at Time 1 and Time 2 (12 months later). According to Time 2 vocabulary size, participants were divided into two groups: Low CCDI, between 0 and 62 words, and High CCDI, more than 100 words. Linear regression was used to examine the relationship between early prelinguistic communication complexity and later expressive language. Binary logistic regression was used to determine which of the early communication behaviours were uniquely significantly related to later expressive language levels.

OUTCOMES & RESULTS

There was a significant positive relationship between prelinguistic communication complexity and expressive language 12 months later, even after controlling for age and concurrent language. Findings revealed a group difference in the frequency of gesture and vocalisation combinations between the Low and High CCDI groups at Time 1. Gesture-vocalisation combinations also predicted better expressive language levels at Time 2.

CONCLUSIONS & IMPLICATIONS

Our findings suggest that it may be beneficial to incorporate different complex communication behaviours into prelinguistic intervention targets for minimally verbal autistic children. The CCS hierarchies can be used as a reference for the intervention goals of minimally verbal autistic children. These findings highlight the importance of targeting gesture and vocalisation combinations when autistic children transition from single prelinguistic communication behaviours to multimodal behaviours.

WHAT THIS PAPER ADDS

What is already known on this subject Children use eye gaze, gestures and vocalisations to communicate with others before they learn spoken language. There is strong evidence suggest that the frequency of prelinguistic communication predicts later linguistic achievements in autistic children. However, less is known about whether prelinguistic communication complexity also predicts later language and which specific behaviours are most predictive of language outcomes. What this study adds Minimally verbal autistic children who exhibit more complex prelinguistic communication behaviours have better expressive language 12 months later. Gestures combined with vocalisations predict better expressive language in minimally verbal autistic children. What are the clinical implications of this work? When identifying intervention targets for minimally verbal autistic children, the clinicians may reference the prelinguistic communication behaviours from the CCS. The gesture and vocalisation combinations are the key behaviours when targets transit from single form to two-form behaviours.

Correlates of infant pointing frequency in the first year

This study examines the emergence of concurrent correlates of infant pointing frequency with the aim of contributing to its ontogenetic theories. We measured monthly from 8 to 12 months infants' (N = 56) index-finger pointing frequency along with several candidate correlates: (1) family socioeconomic status (SES), (2) mothers' pointing production, and (3) infants' point following to targets in front of and behind them. Results revealed that (1) infants increased their pointing frequency across age, but high-SES infants had a steeper increase, and a higher pointing frequency than low-SES infants from 10 months onward, (2) maternal pointing frequency was not associated with infant pointing frequency at any age, (3) infants' point following abilities to targets behind their visual fields was positively associated with their pointing frequency at 12 months, after pointing had already emerged around 10 months. Findings suggest that family SES impacts infants' pointing development more generally, not just through maternal pointing. The association between pointing and following points to targets behind, but not in front, suggests that a higher level of referential understanding emerges after, and perhaps through the production of pointing.

Primordial feeling of possession in development

Boyer's minimalist model of human ownership psychology overlooks important cues that children provide in their development leading them from pre-conceptual to conceptual (symbolic) expressions of the basic feeling experience of control over things, qua ownership in the most basic psychological sense. Appeal for innate core knowledge and evolutionary logic blows out the light of this rich and unique ontogenetic progression.

Experience with pointing gestures facilitates infant vocabulary growth through enhancement of sensorimotor brain activity

Exposure to communicative gestures, through their parents' use of gestures, is associated with infants' language development. However, the mechanisms supporting this link are not fully understood. In adults, sensorimotor brain activity occurs while processing communicative stimuli, including both spoken language and gestures. Using electroencephalogram (EEG) mu rhythm desynchronization (mu ERD), a marker of sensorimotor activity, we examined whether experimental manipulation of infants' exposure to gestures would affect language development, and specifically whether such an effect would be mediated by changes in sensorimotor brain activity. Mu ERD was measured in 10- to 12-month-old infants (N = 81; 42 male; 15% Hispanic, 62% White) recruited from counties surrounding a large mid-Atlantic university while they observed an experimenter gesturing toward or grasping an object. Half of the infants were randomized to receive increased gesture exposure through a parent-directed training. All 81 infants provided behavioral (infant and parent pointing and infant vocabulary) data prior to intervention and 72 provided behavioral data postintervention. Forty-two infants provided usable (post artifact removal) EEG data prior to intervention and 40 infants provided usable EEG data post-intervention. Twenty-nine infants provided usable EEG data at both sessions. Increased parent gesture due to the intervention was associated with increased infant right lateralized mu ERD at follow-up, but only while observing the experimenter gesturing not grasping. Increased mu ERD, again only while observing the experimenter gesture, was associated with increased infant receptive vocabulary. This is the first evidence suggesting that increasing exposure to gestures may impact infants' language development through an effect on sensorimotor brain activity. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Early communicative gestures in human and chimpanzee 1-year-olds observed across diverse socioecological settings

We investigated the communicative gestures used by chimpanzee and human infants. In contrast to previous studies, we compared the species at the same age (12-14 months) and used multiple groups living in diverse socioecological settings for both species. We recorded gestures produced by infants and those produce by others and directed toward infants. We classified the gestures into the following types: human-usual, chimpanzee-usual, and species-common; and searched for within species and between species differences. We found no significant differences between groups or species in overall rates of infant-produced or infant-received gestures, suggesting that all of these infants produced and received gestures at similar levels. We did find significant differences, however, when we considered the three types of gesture. Chimpanzee infants produced significantly higher rates of chimpanzee-usual gestures, and human infants produced significantly higher rates of human-usual gestures, but there was no significant species difference in the species-common gestures. Reports of species differences in gesturing in young infants, therefore, could be influenced by investigators' choice of gesture type. Interestingly, we found that 1-year-old infants produced the gesture of "hold mutual gaze" and that the chimpanzee infants had a significantly higher rate than the human infants. We did not find strong evidence that the specific types of gestural environment experienced by young infants influenced the types of gestures that infants produce. We suggest that at this point in development (before human infants use lots of speech), nonverbal communicative gestures may be equally important for human and chimpanzee infants.

Infants' behaviours elicit different verbal, nonverbal, and multimodal responses from caregivers during early play

Caregivers use a range of verbal and nonverbal behaviours when responding to their infants. Previous studies have typically focused on the role of the caregiver in providing verbal responses, while communication is inherently multimodal (involving audio and visual information) and bidirectional (exchange of information between infant and caregiver). In this paper, we present a comprehensive study of caregivers' verbal, nonverbal, and multimodal responses to 10-month-old infants' vocalisations and gestures during free play. A new coding scheme was used to annotate 2036 infant vocalisations and gestures of which 87.1 % received a caregiver response. Most caregiver responses were verbal, but 39.7 % of all responses were multimodal. We also examined whether different infant behaviours elicited different responses from caregivers. Infant bimodal (i.e., vocal-gestural combination) behaviours elicited high rates of verbal responses and high rates of multimodal responses, while infant gestures elicited high rates of nonverbal responses. We also found that the types of verbal and nonverbal responses differed as a function of infant behaviour. The results indicate that infants influence the rates and types of responses they receive from caregivers. When examining caregiver-child interactions, analysing caregivers' verbal responses alone undermines the multimodal richness and bidirectionality of early communication.

Ontogeny of index-finger pointing

Index-finger pointing is foundational to language acquisition. Less is known about its emergence. In lab-based monthly longitudinal assessments from 8-13 months (N = 31) the study measured longitudinal predictors of index-finger pointing: parent pointing and infants' earlier emerging showing, hand-pointing, and point-following. All behaviors increased significantly with age and showed inter-individual stability. At 11 months all behaviors except hand pointing were synchronously interrelated, with no evidence for an earlier synchronous interrelation between behaviors. Caregiver pointing and infants' earlier behaviors longitudinally predicted the age of emergence of index-finger pointing. An additional cross-sectional comparison of parent pointing at 5 and 7 months (N = 44) showed that significantly fewer caregivers of 5- compared to 7-month-olds pointed for their infants. Findings suggest that pointing emerges as an outcome of social co-construction across the first year of life.

Showing and giving: from incipient to conventional forms

Understanding humans' motivation and capacity for social interaction requires understanding communicative gestures. Gestures are one of the earliest means that infants employ to communicate with others, and showing and giving are among the earliest-emerging gestures. However, there are limited data on the processes that lead up to the emergence of conventional showing and giving gestures. This study aimed to provide such data. Twenty-five infants were assessed longitudinally at monthly intervals from 6 to 10 months of age using a variety of methods (elicitation procedures, free play observations and maternal interviews), as well as via questionnaires conducted at 11-12 months. A particular focus was on pre-conventional, incipient gestures, behaviours that involved some components of conventional gestures, but lacked other important components. We present observational evidence that at least some of these behaviours (observed as early as 7 months of age) were communicative and make the case for how conventional showing and giving may emerge gradually in the context of social interactions. We also discuss the influence of maternal interpretations of these early behaviours on their development. Overall, the study seeks to draw attention to the importance of understanding the cognitive, motor and interactional processes that lead to the emergence of infants' earliest communicative gestures. This article is part of the theme issue 'Revisiting the human 'interaction engine': comparative approaches to social action coordination'.

Infants who experience more adult-initiated conversations have better expressive language in toddlerhood

To understand how infants become engaged in conversations with their caregivers, we examined who tends to initiate conversations between adults and infants, differences between the features of infant- and adult-initiated conversations, and whether individual differences in how much infants engage in infant- or adult-initiated conversations uniquely predict later language development. We analyzed naturalistic adult-infant conversations captured via passive recording of the daily environment in two samples of 6-month-old infants. In Study 1, we found that at age 6 months, infants typically engage in more adult- than infant-initiated conversations and that adult-initiated conversations are, on average, longer and contain more adult words. In Study 2, we replicated these findings and, further, found that infants who engaged in more adult-initiated conversations in infancy had better expressive language at age 18 months. This association remained significant when accounting for the number of infant-initiated conversations at 6 months. Our findings indicate that early interactions with caregivers can have a lasting impact on children's language development, and that the extent to which parents initiate interactions with their infants may be particularly important.