Australian children aged 6-9 years (N = 120, 71 females; data collected in 2021-2022) were tasked with remembering the locations of 1, 3, 5, and 7 targets hidden under 25 cups on different trials. In the critical test phase, children were provided with a limited number of tokens to allocate across trials, which they could use to mark target…

Learning takes time: Performance usually starts poorly and improves with practice. Do children intuit this basic phenomenon of skill learning? In preregistered Experiment 1 (n = 125; 54% female; 48% White; collected 2022-2023), US 7- to 8-year-old children predicted improved performance, 5- to 6-year-old children predicted flat performance, and…

The number line estimation task is frequently used to measure children's numerical magnitude understanding. It is unclear whether the resulting straight, horizontal, left-to-right-oriented estimate patterns indicate task constraints or children's intuitive number--space mapping. Three- to six-year-old children (N = 72, M[subscript age] = 4.89, 56%…

The ability to use knowledge to guide the completion of goals is a critical cognitive skill, but 3-year-olds struggle to complete goals that require multiple steps. This study asked whether 3-year-olds could benefit from "plan chunking" to complete multistep goals. Thirty-two U.S. children (range = 35.75-46.59 months; 18 girls; 9 white,…

Overparenting--taking over and completing developmentally appropriate tasks for children--is pervasive and hurts children's motivation. Can overparenting in early childhood be reduced by simply framing tasks as learning opportunities? In Study 1 (N = 77; 62% female; 74% White; collected 4/2022), US parents of 4-to-5-year-olds reported taking over…

Research with Western samples has uncovered the rapid development of infants' visual attention. This study evaluated spatial attention in 6- to 9-month-old infants living in rural Malawi (N = 511; n[subscript Boys] = 255, n[subscript Yao] = 427) or suburban California, United States (N = 57, n[subscript Boys] = 29, n[subscript White] = 37) in…

We investigated the role of children's conflict monitoring skills in revising an intuitive scientific theory. Children aged 5 to 9 (N = 177; 53% girls, data collected in Germany from 2019-2023) completed computer-based tasks on water displacement, a concept prone to misconceptions. Children predicted which of two objects would displace more water…

Memory decision-making in 26- to 32-month-olds was investigated using visual-paired comparison paradigms, requiring toddlers to select familiar stimuli (Active condition) or view familiar and novel stimuli (Passive condition). In Experiment 1 (N = 108, 54.6% female, 62% White; replication N = 98), toddlers with higher accuracy in the Active…

This study investigates the relations between two forms of joint action (JA)--movement coordination (MC) and goal attainment--and theory of mind (ToM), contrasting the interactionist and traditional cognitivist views. A custom task was carried out to measure the properties of the JAs between children and their parents, while classical tasks were…

Is early reasoning about an agent's knowledge best characterized by a mentalistic stance, a teleological stance, or both? In this research, 5-month-old infants (N = 64, 50% female, 83% White) saw a novel eyeless agent consistently approach object-A as opposed to object-B. Although infants could always see both objects, a screen separated object-B…

This study examined repeating and growing pattern knowledge and their associations with procedural and conceptual arithmetic knowledge in a sample of U.S. children (N = 185; M[subscript age] = 79.5 months; 55% female; 88% White) and adults (N = 93; M[subscript age] = 19.5 years; 62% female; 66% White) from 2019 to 2020. Three key findings emerged:…

People sometimes commit 'egocentric errors', failing to ignore their own perspective when interpreting others' communication. Training imitation-inhibition, when participants perform the opposite action from another person, facilitates subsequent perspective-taking in adults. This study tested whether imitation-inhibition training also facilitates…

This study investigated the development of rapid visual object categorization. N = 20 adults (Experiment 1), N = 21 five to six-year-old children (Experiment 2), and N = 140 four-, seven-, and eleven-month-old infants (Experiment 3; all predominantly White, 81 females, data collected in 2013-2020) participated in a fast periodic visual stimulation…

Place value concepts were measured longitudinally from kindergarten (2017) to first grade (2018) in a diverse sample (n = 279; M[subscript age] = 5.76 years, SD = 0.55; 135 females; 41% Black, 38% White, 8% Asian, 12% Latino). Children completed three syntactic tasks that required an explicit understanding of base-10 symbols and three approximate…

This study explored whether a daytime nap aids children's acquisition of letter-sound knowledge, which is a fundamental component for learning to read. Thirty-two preschool children in Sydney, Australia (M[subscript age] = 4 years;3 months) were taught letter-sound mappings in two sessions: one followed by a nap and the other by a wakeful period.…