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…

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…

Two experiments examined 12- to 13-month-old infants' reactions to noncontingent responding by the parent (Experiment 1, 40 infants) or by an unfamiliar adult (Experiment 2, 40 infants). During the initial play phase, the adult was either reading a book or using his or her mobile phone, resulting in a response delay when the infant would seek the…

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 analyzed the effect of infant-directed speech (IDS) on multimodal communicative production of children at the beginning of the second year of life in two different languages: Spanish and Basque. Twelve Spanish and twelve Basque children aged between 12 and 15 months observed two versions of an audiovisual story: one version was narrated with…

The question of the acquisition of the first social phenomena by newborns is a crucial issue both in understanding the mental development and the ontogenesis of social interaction. The review attempts to investigate other researches that observe social behavior in studies with no communication between subjects. This current analysis reviews…

Functional near-infrared spectroscopy (fNIRS) is a noninvasive neuroimaging technique that could be uniquely effective for investigating cortical function in human infants. However, prior efforts have been hampered by the difficulty of aligning arrays of fNIRS optodes placed on the scalp to anatomical or functional regions of underlying cortex.…

Seven- to 12-month-olds were trained to press levers that contingently activated lights. Infants had the choice of turning on either a light an adult interaction partner was looking at or a light that she turned away from. By 9 months, infants reliably turned on the light that the adult was looking at. In a second study, 9- and 12-month-old…

In this study, we address the construction of the first symbolic uses of objects in contexts of triadic interaction (adult-child-object). We assume that symbolic productions are based on public rules of the use of objects previously agreed by the community. The first symbols are not rooted in any literal, evident reality, but in shared rules of…

Saccade latency is widely used across infant psychology to investigate infants' understanding of events. Interpreting particular latency values requires knowledge of standard saccadic RTs, but there is no consensus as to typical values. This study provides standard estimates of infants' (n = 194, ages 9 to 15 months) saccadic RTs under a range of…

Infants' preference for faces was investigated in a cross-sectional sample of 75 children, aged 3 to 11 months, and 23 adults. A visual preference paradigm was used where pairs of faces and toys were presented side-by-side while eye gaze was recorded. In addition, motor activity was assessed via parent report and the relation between motor…

Adult-infant interactions operate simultaneously across multiple domains and at multiple levels -- from physiology to behaviour. Unpackaging and understanding them, therefore, involve analysis of multiple data streams. In this study, we tested physiological responses and cognitive preferences for infant and adult faces in adult females and males.…

Studies investigating imitation are usually conducted with adult models in Western contexts; therefore, the influence of cultural context and the model's age on infants' imitation is largely unknown. This study assessed deferred imitation in 9-month-old infants from the German middle-class ("N" = 44) and the ethnic group of Nso in rural…

This study employed a new "anticipatory intervening" paradigm to tease apart false belief and ignorance-based interpretations of 18-month-olds' helpful informing. We investigated in three experiments whether 18-month-old infants inform an adult selectively about one of the two locations depending on the adult's belief about which of the two…

Warning others is a paradigm case of communicative helping and prospective action understanding. The current study addressed the ontogeny of warning in infants' gestural communication. We found that 12- and 18-month-olds ("n" = 84) spontaneously warned an adult by pointing out to her an aversive object hidden in her way…