Pacifier use during childhood has been hypothesized to interfere with language processing, but, to date, there is limited evidence revealing detrimental effects of prolonged pacifier use on infant vocabulary learning. In the present study, parents of 12- and 24-month-old infants were recruited in Oslo (Norway). The sample included 1187 monolingual…

Research with Western samples has uncovered the rapid development of infants' visual attention. This study evaluated spatial attention in 6- to 9-month-old infants living in rural Malawi (N = 511; n[subscript Boys] = 255, n[subscript Yao] = 427) or suburban California, United States (N = 57, n[subscript Boys] = 29, n[subscript White] = 37) in…

The secure base phenomenon was ascribed to changes in exploration observed during Ainsworth's Strange Situation Procedure (SSP), related to the quality of the attachment relationship. However, infant temperament was not taken into consideration. The current study aims to replicate Ainsworth's findings regarding infant exploration and attachment…

This study aimed to investigate how mothers and infants contribute mutually to breastfeeding. The spontaneous interactions of 20 breastfeeding dyads were video-recorded at home, at 2, 4, 6, 9 and 12 months of infants' life. Mothers' and infants' gaze and tactile behaviour, facial expressions of emotion, and dyadic expressions were continuously…

Infant pointing is predictive of later language development, but little is known about factors enhancing the development of pointing. The current study investigated two possible social learning mechanisms in the development of pointing. Given that infants observe their caregivers' pointing gestures from early on, one possibility is learning via…

Process praise (i.e., praise for effort) facilitates childhood persistence. However, less is known about the mechanism by which process praise influences persistence in infancy. Here, we propose that well-timed process praise reinforces the link between effort and success, thus promoting persistence in young children. In Experiment 1, U.S. infants…

By 12 months of age, infants exhibit behavioral sensitivity to sound symbolism (e.g. sound-shape correspondences) when they hear universally sound symbolic pseudowords (e.g. "bouba," "kiki"). Here, we investigated whether infant's sensitivity to sound-shape correspondences is affected when they hear language-specific sound…

For those experiencing them, educational transitions include not only the present time but are embedded within institutions that precede and extend beyond the individuals. This article explores how, as an institutional space, the early childhood education and care (ECEC) setting is (re)produced within young children's encounters with others during…

Adaptive behaviour refers to the everyday skills that individuals are expected to have to function independently, based on their age and societal norms. Currently, we know little about the role of genetic and environmental factors in parent-rated adaptive behaviours in early infancy. The aim of this study was to investigate the aetiological…

Being looked at is an important communicative signal, and attenuated responses to such direct gaze have been suggested as an early sign of autism. Using live eye tracking, we examined whether direct gaze elicits different gaze responses in infants at ages 10, 14 and 18 months with and without later autism in real-life interaction. The sample…

It is known that infant-directed speech (IDS) plays a key role in language development. Previous research, however, has also identified significant variability across societies in terms of how often IDS occurs. For example, some studies report very little IDS in non-western, small-scale societies -- including children growing up in small-scale…

What are the vocal experiences of children growing up on Malakula island, Vanuatu, where multilingualism is the norm? Long-form audio-recordings captured spontaneous speech behavior by, and around, 38 children (5-33 months, 23 girls) from 11 villages. Automated analyses revealed most children's vocal input came from female adults and other…

This study examined the extent to which the quality of teacher-infant interactions varies across play and routine care activities. In addition, the effects of the quantity of adult involvement in the quality of teacher-infant interactions were investigated. Participants were teachers and infants from 90 infant classrooms in Portugal. Classrooms…

We assessed whether the negative association between maternal postpartum depression (PPD) and infants' development of joint attention (gaze following) generalizes from WEIRD (Western, Educated, Industrialized, Rich, and Democratic) to Majority World contexts. The study was conducted in Bhutan (N = 105, M = 278 days, 52% males) but also draws from…

We compared maternal speech in interactions of mothers with their firstborn dizygotic twin and singleton infants. Nine twins and nine singletons were video-recorded at home in spontaneous face-to-face interactions with their mothers, from the 2nd to the 6th month. Continuous micro-analysis revealed that there are more quantitative and qualitative…