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…

Infants are born highly sensitive to the natural patterns found in languages. They use their perceptual sensitivity to acquire detailed information about the structure of languages in their environment. To date, most studies of infant perception and early language acquisition have investigated spoken/auditory languages and hearing infants (e.g.…

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 behavior of newborns is ambiguous. Cultural models--representations shared by members of a community--provide new parents and others with a cognitive and motivational structure to understand them. This study asks members of several cultural groups (total n = 100) to judge the "similarity" of behavioral items in the Neonatal…

This study captures the possibilities of infants' interactions in a Brazilian Early Childhood Education Centre. It contributes to an increasing number of educational research that is capturing the specificities of how young children use their understandings of context through gestures and verbal forms of language to create meanings as they develop…

This study establishes a sequence of developing mental state understandings in infants. We used three violation-of-expectation paradigms to assess fifty-seven 16-month-olds' ability to (a) infer an actress's intention from her prior repeated approaches to an object, (b) recognize her emotion by watching her facial-emotional display, and (c) deduce…

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…

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…

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…

This study examines the construct validity of the First-Year Inventory 2.0 with respect to other established instruments in a sample of high-risk infant siblings of children with Autism Spectrum Disorder. The First-Year Inventory 2.0 is a parent-report screening instrument designed to identify 12-month-old infants at risk for an eventual diagnosis…

The development of copying behaviours of a group of infants from 9 to 15 months of age is analysed. These behaviours are classified according to their type (mimetic or imitated) and function (instrumental, social or hybrid). The function of the behaviours is derived from observable indicators linked to dyadic interaction. Mimetic behaviours are…

A live video was used to study the development of visual self-recognition in a cross-sectional sample of 152 typically developing French children aged between 15 months to 6 years. Three reactions to a mark placed on the child's cheek without their knowledge were studied: the touch of the mark with their hand, the ocular responsiveness to the mark…

This study used an ethological approach to explore the behavioural adaptation of nineteen infants during their first six weeks in Residential Care (RC), or a Foster Family (FF) or an Infant-Mother Centre (IMC). Direct observations were conducted once a week at bath time. Observed behaviours were: sleep-wake states, visual exploration, motor…

Fragmented sleep is common in infancy. Although night awakening is known to decrease with age, in some infants night awakening is more persistent and continues into older ages. However, the influence of fragmented sleep on development is poorly known. In the present study, the longitudinal relationship between fragmented sleep and psychomotor…