We investigate when infants exhibit knowledge of the familiar size of well-known objects and whether this knowledge is affected by stimulus format, that is, whether the stimuli are presented as real objects or matched pictures. Infants (130 7- and 12-month-olds) saw everyday objects such as sippy cups and pacifiers in their familiar size and novel…

Adults and children easily distinguish between fine-grained variations in trustworthiness intensity based on facial appearance, but the developmental origins of this fundamental social skill are still debated. Using a fast periodic visual stimulation (FPVS) oddball paradigm coupled with electroencephalographic (EEG) recording, we investigated…

We tested 4-6- and 10-12-month-old infants to investigate whether the often-reported decline in infant sensitivity to other-race faces may reflect responsiveness to static or dynamic/silent faces rather than a general process of perceptual narrowing. Across three experiments, we tested discrimination of either dynamic own-race or other-race faces…

This research investigated whether the perception of social-causal relation alone triggers both infants' evaluation processes and expectations about the social preferences of informed third parties. Three experiments were carried out, using the violation of expectation (VoE) paradigm. During the familiarization phase, infants saw events in which…

Research demonstrating that infants discriminate between small (e.g., 1 vs. 3 dots) and large numerosities (e.g., 8 vs. 16 dots) is central to theories concerning the origins of human numerical abilities. To date, there has been no quantitative meta-analysis of the infant numerical competency data. Here, we quantitatively synthesize the evidential…

This research examined whether infants tested longitudinally at 10, 14, and 16 months of age (N = 58) showed evidence of perceptual narrowing based on face gender (better discrimination of female than male faces) and whether changes in caregiving experience longitudinally predicted changes in infants' discrimination of male faces. To test face…

Although research has demonstrated impressive face perception skills of young infants, little attention has focused on conditions that enhance versus impair infant face perception. The present studies tested the prediction, generated from the intersensory redundancy hypothesis (IRH), that face discrimination, which relies on detection of visual…

Faces are visually attractive to both human and nonhuman primates. Human neonates are thought to have a broad template for faces at birth and prefer face-like to non-face-like stimuli. To better compare developmental trajectories of face processing phylogenetically, here, we investigated preferences for face-like stimuli in infant rhesus macaques…

The present studies examined the role of linguistic experience in directing English and Mandarin learners' attention to aspects of a visual scene. Specifically, they asked whether young language learners in these 2 cultures attend to differential aspects of a word-learning situation. Two groups of English and Mandarin learners, 6-8-month-olds (n =…

Previous studies have proposed that humans may be born with mechanisms that attend to conspecifics. However, as previous studies have relied on stimuli featuring human adults, it remains unclear whether infants attend only to adult humans or to the entire human species. We found that 1-month-old infants (n = 23) were able to differentiate between…

This experiment investigated social referencing as a form of discriminative learning in which maternal facial expressions signaled the consequences of the infant's behavior in an ambiguous context. Eleven 4- and 5-month-old infants and their mothers participated in a discrimination-training procedure using an ABAB design. Different consequences…

Adults recognize emotions conveyed by bodies with comparable accuracy to facial emotions. However, no prior study has explored infants' perception of body emotions. In Experiment 1, 6.5-month-olds (n = 32) preferred happy over neutral actions of actors with covered faces in upright but not inverted silent videos. In Experiment 2, infants…

Previous studies have revealed that young infants can distinguish between displays of possible or impossible figures, which may require detection of inconsistent depth relations among local line junctions that disrupt global object configurations. Here, we used an eye-tracking paradigm to record eye movements in young infants during an object…

Event-related potentials (ERPs) were utilized in an investigation of 21 six-month-olds' attention to and processing of global and local properties of hierarchical patterns. Overall, infants demonstrated an advantage for processing the overall configuration (i.e., global properties) of local features of hierarchical patterns; however,…

Infants search for an object hidden by an occluder in the light months later than one hidden by darkness. One explanation attributes this decalage to easier action demands in darkness versus occlusion, whereas another attributes it to easier representation demands in darkness versus occlusion. However, search tasks typically confound these two…