Psychological scientists have become increasingly concerned with issues related to methodology and replicability, and infancy researchers in particular face specific challenges related to replicability: For example, high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations. Addressing these concerns, we report on a large-scale, multisite study aimed at (a) assessing the overall replicability of a single theoretically important phenomenon and (b) examining methodological, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult in North American English were created using seminaturalistic laboratory-based audio recordings. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three common methods for measuring infants’ discrimination (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s d) was 0.35, 95% confidence interval = [0.29, 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together, these findings replicate the IDS preference but suggest that its magnitude is modulated by development, native-language experience, and testing procedure.

Languages instantiate many different kinds of dependencies, some holding between adjacent elements and others holding between nonadjacent elements. In the domain of phonology–phonotactics, sensitivity to adjacent dependencies has been found to appear between 6 and 10 months. However, no study has directly established the emergence of sensitivity to nonadjacent phonological dependencies in the native language. The present study focuses on the emergence of a perceptual Labial‐Coronal (LC) bias, a dependency involving two nonadjacent consonants. First, Experiment 1 shows that a preference for monosyllabic consonant‐vowel‐consonant LC words over CL (Coronal‐Labial) words emerges between 7 and 10 months in French‐learning infants. Second, two experiments, presenting only the first or last two phonemes of the original stimuli, establish that the LC bias at 10 months cannot be explained by adjacent dependencies or by a preference for more frequent coronal consonants (). At 7 months, by contrast, infants appear to react to the higher frequency of coronal consonants (). The present study thus demonstrates that infants become sensitive to nonadjacent phonological dependencies between 7 and 10 months. It further establishes a change between these two ages from sensitivity to local properties to nonadjacent dependencies in the phonological domain.

Older children with online schooling requirements, unsurprisingly, were reported to have increased screen time during the first COVID-19 lockdown in many countries. Here, we ask whether younger children with no similar online schooling requirements also had increased screen time during lockdown. We examined children’s screen time during the first COVID-19 lockdown in a large cohort (n = 2209) of 8-to-36-month-olds sampled from 15 labs across 12 countries. Caregivers reported that toddlers with no online schooling requirements were exposed to more screen time during lockdown than before lockdown. While this was exacerbated for countries with longer lockdowns, there was no evidence that the increase in screen time during lockdown was associated with socio-demographic variables, such as child age and socio-economic status (SES). However, screen time during lockdown was negatively associated with SES and positively associated with child age, caregiver screen time, and attitudes towards children’s screen time. The results highlight the impact of the COVID-19 lockdown on young children’s screen time.

Previous work has shown that preterm infants are at higher risk for cognitive/language delays than full-term infants. Recent studies, focusing on prosody (i.e. rhythm, intonation), have suggested that prosodic perception development in preterms is indexed by maturational rather than postnatal/listening age. However, because prosody is heard in-utero, and preterms thus lose significant amounts of prenatal prosodic experience, both their maturation level and their prosodic experience (listening age) are shorter than that of full-terms for the same postnatal age. This confound does not apply to the acquisition of phonetics/phonotactics (i.e. identity and order of consonants/vowels), given that consonant differences in particular are only perceived after birth, which could lead to a different developmental pattern. Accordingly, we explore the possibility that consonant-based phonotactic perception develops according to listening age. Healthy French-learning full-term and preterm infants were tested on the perception of consonant sequences in a behavioral paradigm. The pattern of development for full-term infants revealed that 7-month-olds look equally at labial-coronal (i.e. /pat/) compared to coronal-labial sequences (i.e. /tap/), but that 10-month-olds prefer the labial-coronal sequences that are more frequent in the French lexicon. Preterm 10-month-olds (having 10 months of phonetic listening experience but 7 months of maturational age) behaved as full-term 10-month-olds. These results establish that preterm developmental timing for consonant-based phonotactic acquisition is based on listening age (experience with input). This questions the interpretation of previous results on prosodic acquisition in terms of maturational constraints, and raises the possibility that different constraints apply to the acquisition of different phonological subcomponents.

High‐quality, centre‐based education and care during the early years benefit cognitive development, especially in children from disadvantaged backgrounds. During the COVID‐19 pandemic and its associated lockdowns, access to early childhood education and care (ECEC) was disrupted. We investigate how this period affected the developmental advantages typically offered by ECEC. Using parent‐report data from 189 families living in the UK, we explore associations between time spent in ECEC by 8‐to‐36‐month‐olds, their socioeconomic background, and their growth in language and executive functions between Spring and Winter 2020. Receptive vocabulary growth was greater in children who continued to attend ECEC during the period, with a stronger positive effect for children from less advantaged backgrounds. The growth of cognitive executive functions (CEFs) was boosted by ECEC attendance during the period, regardless of socioeconomic background. Our findings highlight the importance of high‐quality ECEC for the development of key skills and for levelling socioeconomic inequalities.

Early executive functions (EFs) lay the foundations for academic and social outcomes. In this parent-report study of 575 UK-based 8-to 36 month olds (218 followed longitudinally), we investigate how variation in the home environment before and during the 2020 pandemic relates to infants' emerging EFs. Parent-infant enriching activities were positively associated with infant Cognitive Executive Function (CEF) (encompassing inhibitory control, working memory, cognitive flexibility). During the most-restrictive UK lockdownbut not subsequently-socioeconomic status (SES) was positively associated with levels of parent-infant enriching activities. Parents who regard fostering early learning, affection, and attachment as important were more likely to engage in parent-infant enriching activities, yet there was no significant pathway from parental attitudes or SES to CEF via activities. Infant screen use was negatively associated with CEF and Regulation. Screen use fully mediated the effect of SES on CEF, and partially mediated the effect of SES on regulation.

Characterizing the nature of linguistic representations and how they emerge during early development is a central goal in the cognitive science of language. One area in which this development plays out is in the acquisition of dependencies-relationships between co-occurring elements in a word, phrase, or sentence. These dependencies often involve multiple levels of representation and abstraction, built up as infants gain experience with their native language. The authors used the Headturn Preference Procedure to systematically investigate the early acquisition of 1 such dependency, the agreement between a subject and verb in French, at 6 different ages between 14 and 24 months. The results reveal a complex developmental trajectory that provides the first evidence that infants might indeed progress through distinct stages in the acquisition of this nonadjacent dependency. The authors discuss how changes in general cognition and representational knowledge (from reflecting surface statistics to higher-level morphological features) might account for their findings. These findings highlight the importance of studying language acquisition at close time intervals over a substantial age range. (PsycINFO Database Record

Many studies have shown that during the first year of life infants start learning the prosodic, phonetic and phonotactic properties of their native language. In parallel, infants start associating sound sequences with semantic representations. However, the question of how these two processes interact remains largely unknown. The current study explores whether (and when) the relative phonotactic probability of a sound sequence in the native language has an impact on infants’ word learning. We exploit the fact that Labial-Coronal (LC) words are more frequent than Coronal-Labial (CL) words in French, and that French-learning infants prefer LC over CL sequences at 10 months of age, to explore the possibility that LC structures might be learned more easily and thus at an earlier age than CL structures. Eye movements of French-learning 14- and 16-month-olds were recorded while they watched animated cartoons in a word learning task. The experiment involved four trials testing LC sequences and four trials testing CL sequences. Our data reveal that 16-month-olds were able to learn the LC and CL words, while14-month-olds were only able to learn the LC words, which are the words with the more frequent phonotactic pattern. The present results provide evidence that infants’ knowledge of their native language phonotactic patterns influences their word learning: Words with a frequent phonotactic structure could be acquired at an earlier age than those with a lower probability. Developmental changes are discussed and integrated with previous findings.