Labeling objects enhances fundamental cognitive capacities like categorization, individuation, and memory in young chil-dren. However, the mechanism by which labels support these cognitive processes remains unknown. One possibility isthat providing a label for an object changes childrens online visual processing of that object. To address this, we consid-ered several indices of visual attention, asking whether 2-year-old children attend to an object differently if it is labeled(Look at the dax) than if it is paired with a non-labeling phrase (Look at that). We find that 2-year-old childrens visualfixations are longer when objects are paired with a labeling phrase, rather than a non-labeling phrase. Indeed, after hearinga label, children showed a sustained increase in fixation duration. However, the number of fixations children made did notchange as a function of labeling. This illustrates an attentional mechanism by which language might enhance learning in2-year-old children.

In both gesture and sign, objects and events can be represented by reproducing some of their features iconically.Iconic gestures do not typically appear until well into children’s second year of life, suggesting that the cognitive and/or com-municative resources required are not trivial. Here we investigate how manual iconicity develops in two different communica-tive systems. Using longitudinal video corpora, we compare the emergence of manual iconicity in 52 hearing children learninga spoken language (co-speech gesture) to a deaf child creating a manual communication system (homesign). We focus on theshape of the hand, asking how handshape use changes between age 1 and 5, and how handshape choice relates to semanticcontent. We find broadly similar patterns of handshape development in co-speech gesture and homesign. This suggests that thecognitive building blocks underlying children’s ability to iconically map forms to meanings are shared across vastly differentcommunicative systems.

Inclusion of gesture – meaningful movements of the hands –during mathematics instruction is beneficial for teachingnaïve learners novel concepts, and it can affect a learner’sallocation of visual attention. Yet, it is unknown how childrenwith pre-existing knowledge of a math concept approachinstruction that includes gesture. Here, we examine howchildren’s prior knowledge and either the presence or absenceof gesture during instruction drive patterns in visual attentionduring a lesson. We find that prior knowledge does determinevisual attention patterns, independent of type of instruction(i.e. with or without gesture). These findings further ourunderstanding of the attentional mechanisms of gesture andhave implications for real-world classrooms, where levels ofprior knowledge are often mixed.

To learn from others, children rely on cues (e.g., familiarity) toinfer who will provide useful information. We extend thisresearch to ask whether children will use an informant’sinclination to gesture as a marker of whether they are a goodperson to learn from. Children (N=459, ages 4-12 years)watched videos in which actresses made statementsaccompanied by meaningful iconic gestures, beat gestures, orno gestures. After each trial, children were asked “Who do youthink would be a good teacher?” (good teacher- experimentalcondition) or “Who do you think would be a good friend?”(good friend-control condition). Results show children dobelieve that someone who produces iconic gesture would makea good teacher over someone who does not, but this is only laterin childhood and only if a child has the propensity to seegesture as meaningful. The same effects were not found in thegood-friend condition.

Teaching a new concept with gestures – hand movements thataccompany speech – facilitates learning above-and-beyondinstruction through speech alone (e.g., Singer & Goldin-Meadow, 2005). However, the mechanisms underlying thisphenomenon are still being explored. Here, we use eyetracking to explore one mechanism – gesture’s ability todirect visual attention. We examine how children allocatetheir visual attention during a mathematical equivalencelesson that either contains gesture or does not. We show thatgesture instruction improves posttest performance, andadditionally that gesture does change how children visuallyattend to instruction: children look more to the problem beingexplained, and less to the instructor. However lookingpatterns alone cannot explain gesture’s effect, as posttestperformance is not predicted by any of our looking-timemeasures. These findings suggest that gesture does guidevisual attention, but that attention alone cannot account for itsfacilitative learning effects.

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.