This study investigated the systematic rise in cognitive ability scores over generations, known as the "Flynn Effect," across middle childhood and early adolescence (7-15 years; 291 monozygotic pairs, 298 dizygotic pairs; 89% White). Leveraging the unique structure of the Louisville Twin Study (longitudinal data collected continuously…

Academic cheating is common, but little is known about its early emergence. It was examined among Chinese second to sixth graders (N = 2094; 53% boys, collected between 2018 and 2019) using a machine learning approach. Overall, 25.74% reported having cheated, which was predicted by the best machine learning algorithm (Random Forest) at a mean…

Intellectual performance is highly heritable and robustly predicts lifelong health and success but the earliest manifestations of genetic effects on this asset are not well understood. This study examined whether early executive function (EF) or verbal performance mediate genetic influences on subsequent intellectual performance, in 561 U.S.-based…

Dialogic reading, when children are read a storybook and engaged in relevant conversation, is a powerful strategy for fostering language development. With the development of artificial intelligence, conversational agents can engage children in elements of dialogic reading. This study examined whether a conversational agent can improve children's…

Early life stress (ELS) is associated with lower IQ and academic achievement; however, it remains unclear whether it additionally explains their discrepancy. In 2,401 children (54% girls, 30.2% migration background) from the population-based study Generation R Study, latent factors of prenatal and postnatal (age 0-10) ELS were estimated, and…

This paper estimates the acute effect of community-level homicides on early childhood language development and explores the moderating role of maternal efficacy and satisfaction in Chile. It uses data from the 2017 wave of the Early Childhood Longitudinal Survey of Chilean Children (N = 1194, M[subscript age]: 52.8 months, 52% girls). Children in…

Children's math learning (N = 217; M[subscript age] = 4.87 years; 63% European American, 96% college-educated families) from an intelligent character game was examined via social meaningfulness (parasocial relationships [PSRs]) and social contingency (parasocial interactions, e.g., math talk). In three studies (data collected in the DC area:…

Helping has many positive consequences for both helpers and recipients. However, in the present research, we considered a possible downside to receiving help: that it signals a deficiency. We investigated whether young children make inferences about intelligence from observing some groups of people receive help and other groups not. In a novel…

Gifted underachievers perform worse in school than would be expected based on their high intelligence. Possible causes for underachievement are low motivational dispositions (need for cognition) and metacognitive competences. This study tested the interplay of these variables longitudinally with gifted and non-gifted students from Germany…

Phonological difficulties characterize children with developmental dyslexia across languages, but whether impaired auditory processing underlies these phonological difficulties is debated. Here the causal question is addressed by exploring whether individual differences in sensory processing predict the development of phonological awareness in 86…

The Wechsler Preschool and Primary Scale of Intelligence, 4th ed. includes two measures of working memory normed on children 2;6-7;7. The present analyses of the typically developing children (N = 1,591, 812 female, 779 male, with an ethnic distribution approximating the United States) provide new, theoretically important information about these…

This study assessed the developmental profile of unisensory and multisensory processes, and their contribution to children's intellectual abilities (8- and 11-year olds, N = 38, compared to adults, N = 19) using a simple audiovisual detection task and three incidental associative learning tasks with different sensory signals: visual-verbal with…

This 5-year longitudinal study investigated advanced theory-of-mind (AToM) development in 161 German 5- to 10-year-olds (89 females, 72 males). Core aspects of AToM developed nonlinearly, with children reaching a milestone at the age of 7 years, around when they attained the conceptual insight that mental states can be recursive. In late…

The evidence for negative influences of maternal stress during pregnancy on child cognition remains inconclusive. This study tested the association between maternal prenatal stress and child intelligence in 4,251 mother-child dyads from a multiethnic population-based cohort in the Netherlands. A latent factor of prenatal stress was constructed,…

The study investigated whether age at attainment of 20 developmental milestones within the areas of language, walking, eating, dressing, social interaction, and toilet training was associated with adult intelligence. Mothers of 821 children of the Copenhagen Perinatal Cohort recorded 20 developmental milestones at a 3-year examination, and all…