Developmental research, like many fields, is plagued by low sample sizes and inconclusive findings. The problem is amplified by the difficulties associated with recruiting infant participants for research as well as the increased variability in infant responses. With sequential testing designs providing a viable alternative to paradigms facing…

Infants' ability to perform visual short-term memory (VSTM) tasks develops rapidly between 6 and 8 months. Here we tested the hypothesis that infants' VSTM performance is influenced by their ability to individuate simultaneously presented objects. We used a "one-shot change detection task" to ask whether 6-month-old infants (N = 47)…

Considerable studies have shown the protective effects of breastfeeding on internalizing problem behaviours in early childhood, yet little is known about the groundwork for this relationship. This study attempted to test the hypothesis that improvement of mothers' positive parenting behaviours by breastfeeding can explain the relationship. We used…

Infants learning languages with long consonants, or geminates, have been found to "overselect" and "overproduce" these consonants in early words and also to commonly omit the word-initial consonant. A production study with thirty Italian children recorded at 1;3 and 1;9 strongly confirmed both of these tendencies. To test the…

Five-month-old infants selectively attend to novel people who sing melodies originally learned from a parent, but not melodies learned from a musical toy or from an unfamiliar singing adult, suggesting that music conveys social information to infant listeners. Here, we test this interpretation further in older infants with a more direct measure of…

Recent evidence from studies using head cameras suggests that the frequency of faces directly in front of infants "declines" over the first year and a half of life, a result that has implications for the development of and evolutionary constraints on face processing. Two experiments tested 2 opposing hypotheses about this observed…

The ability to compute non-adjacent regularities is key in the acquisition of a new language. In the domain of phonology/phonotactics, sensitivity to non-adjacent regularities between consonants has been found to appear between 7 and 10 months. The present study focuses on the emergence of a posterior-anterior (PA) bias, a regularity involving two…

The Tennessee Department of Education (TDOE) discovered that infants and toddlers who were referred for Part C services and initially found ineligible for a full evaluation through screening were being re-referred and later found eligible for services at a high rate. This report presents the systematic evaluation process that TDOE's Tennessee…

Objective: To assess the relationship of moderate and late preterm birth (32[superscript 0/7]-36 [superscript 6/7] weeks) to long-term educational outcomes. Study Design: We hypothesized that moderate and late preterm birth would be associated with adverse out- comes in elementary school. To test this, we linked vital statistics patient discharge…

Some students taking infant development classes have limited, direct experience of interacting with infants. This paper reports on a pilot of an innovative, research-informed workshop that provides hands-on experience through the use of infant simulators. The workshop adapted the Leiden Infant Sensitivity Simulator Assessment, which uses the…

Infants have shown variable success in quantity comparison tasks, with infants of a given age sometimes successfully discriminating numerical differences at a 2:3 ratio but requiring 1:2 and even 1:4 ratios of change at other times. The current explanations for these variable results include the two-systems proposal--a theoretical framework that…

How to measure quality of early childhood education and care is an evergreen topic of research and discussion in various disciplines. Here, we propose a contribution from developmental neuroscience and neuroendocrinology. In this secondary data analysis study, we tested the hypothesis that salivary cortisol can serve as a reliable objective…

Cumulative vocabulary models for infants and toddlers were developed from models of learning that predict trajectories associated with low, average, and high vocabulary growth rates (14 to 46 months). It was hypothesized that models derived from rates of learning mirror the type of exchanges provided to infants and toddlers by parents and…

Given the centrality of prosociality in everyday social functioning, understanding the factors and mechanisms underlying the origins of prosocial development is of critical importance. This experiment investigated whether experience with reciprocal object exchanges can drive the developmental onset of sharing behavior. Seven-month-old infants took…

Adults often attribute internal dispositions to other people and down-play situational factors as explanations of behavior. A few studies have addressed the origins of this proclivity, but none has examined emotions, which rank among the more important dispositions that we attribute to others. Two experiments (N = 270) explored 15-month-old…