We investigated whether 12-month-old infants rely on information about the certainty of goal selection in order to predict observed reaching actions. Infants' goal-directed gaze shifts were recorded as they observed action sequences in a multiple-goals design. We found that 12-month-old infants exhibited gaze shifts significantly earlier when…

Over the past few decades, there has been extensive debate as to whether humans represent number abstractly and, if so, whether perceptual features of a set such as cumulative surface area or contour length are extracted more readily than number from the external world. Here we show that 7-month-old infants are sensitive to smaller ratio changes…

In human newborns, spontaneous visual preference for biological motion is reported to occur at birth, but the factors underpinning this preference are still in debate. Using a standard visual preferential looking paradigm, 4 experiments were carried out in 3-day-old human newborns to assess the influence of translational displacement on perception…

This research examined the development of adaptive generalization in infants' object-directed actions. Infants ages 9 and 12 months participated in an object manipulation task with stimulus objects from 2 categories that differed in shape and weight and that bore a consistent shape or weight correspondence. Weight differences between…

The present investigation explored the question of whether walking onset is related to infant language development. Study 1 used a longitudinal design (N = 44) to assess infant locomotor and language development every 2 weeks from 10 to 13.5 months of age. The acquisition of walking was associated with a significant increase in both receptive and…

The present study investigated young preschoolers' proportional allocation of rewards in 2 different work contexts. We presented 32 pairs of 3.5-year-old peers with a collaborative task to obtain rewards by pulling ropes. In order to establish differences in work input, 1 child's rope was not immediately accessible but had to be…

Zimmerman, Christakis, and Meltzoff (2007) reported that exposure to Baby Einstein videos was negatively associated with language development. The current study uses the Zimmerman et al. (2007) data set to replicate and extend the original analyses. Caregivers of 392 children aged 6 to 16 months and 358 children aged 17 to 27 months reported on…

Handedness for acquiring objects was assessed monthly from 6 to 14 months in 328 infants (182 males). A group based trajectory model identified 3 latent groups with different developmental trajectories: those with an identifiable right preference (38%) or left preference (14%) and those without an identifiable preference (48%) but with a…

To make a scientific contribution, a reanalysis must be firmly rooted in the identification of a clearly superior methodological innovation over the original research. By contrast, a reanalysis rooted in dissatisfaction with previous results will necessarily be biased and can only obscure scientific discoveries. The reanalysis published by…

Zimmerman (2014) suggested that our reanalysis adds little to the scientific literature. We disagree. We clarify our motivations and explain how further analyses based on his suggestion for age do not change our conclusions. Moreover, we believe the nascent experimental literature is more in line with our interpretations than Zimmerman's. We…

Early selective attention skills are a crucial building block for cognitive development, as attention orienting serves as a primary means by which infants interact with and learn from the environment. Although several studies have examined infants' attention orienting using the spatial cueing task, relatively few studies have examined…

Despite the large body of knowledge on adults suggesting that 2 basic types of mental spatial transformation--namely, object-based and egocentric perspective transformations--are dissociable and specialized for different situations, there is much less research investigating the developmental aspects of such spatial transformation systems. Here, an…

Moment-to-moment intraindividual variability (IIV) in cognitive speed is a sensitive behavioral indicator of the integrity of the aging brain and brain damage, but little information is known about how IIV changes from being relatively low in young adulthood to substantially higher in older adulthood. We evaluated possible age group, sex, and task…

Aging-related declines occur in many different domains of cognitive function during middle and late adulthood. However, whether a global dimension underlies individual differences in changes in different domains of cognition and whether global genetic influences on cognitive changes exist is less clear. We addressed these issues by applying…

Elevated levels of risky behavior in adolescence may signal developmental change in unconscious appraisal of risk. Yet, prior research examining adolescent risk judgment has used tasks that elicit conscious deliberation. The present study, in contrast, attempts to characterize age differences in (less conscious) intuitive impressions of risk.…