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…

The current study used a novel methodology based on multivocal ethnography to assess the relations between conformity and evaluations of intelligence and good behavior among Western (U.S.) and non-Western (Ni-Vanuatu) children (6- to 11-year-olds) and adolescents (13- to 17-year-olds; N = 256). Previous research has shown that U.S. adults were…

This study explored developmental and individual differences in intellectual humility (IH) among 127 children ages 6-8. IH was operationalized as children's assessment of their knowledge and willingness to delegate scientific questions to experts. Children completed measures of IH, theory of mind, motivational framework, and intelligence, and…

Cognitive impairment is common among children born very preterm (VPT), yet little is known about how this risk changes over time. To examine this issue, a regional cohort of 110 VPT (= 32 weeks gestation) and 113 full-term (FT) born children was prospectively assessed at ages 4, 6, 9, and 12 years using the Wechsler Preschool and Primary Scale of…

The study examined the etiology of individual differences in early drawing and of its longitudinal association with school mathematics. Participants (N = 14,760), members of the Twins Early Development Study, were assessed on their ability to draw a human figure, including number of features, symmetry, and proportionality. Human figure drawing was…

The purpose of this study was to empirically examine the dimensionality of language ability for young children (4-8 years) from prekindergarten to third grade (n = 915), theorizing that measures of vocabulary and grammar ability will represent a unitary trait across these ages, and to determine whether discourse skills represent an additional…

The authors examined 284 maltreated and nonmaltreated children's (6- to 12-year-olds) ability to inhibit true and false memories for neutral and emotional information using the Deese/Roediger-McDermott (DRM) paradigm. Children studied either emotional or neutral DRM lists in a control condition or were given directed-remembering or…

A large-scale ("N" = 552) controlled multivariate prospective 14-year longitudinal study of a developmental cascade embedded in a developmental system showed that information-processing efficiency in infancy (4 months), general mental development in toddlerhood (18 months), behavior difficulties in early childhood (36 months),…

This research examined how motivation (perceived control, intrinsic motivation, and extrinsic motivation), cognitive learning strategies (deep and surface strategies), and intelligence jointly predict long-term growth in students' mathematics achievement over 5 years. Using longitudinal data from six annual waves (Grades 5 through 10;…

Academic achievement and cognitive ability have been shown to predict later age at first sexual intercourse. Using a sample of 536 same-sex twin pairs who were followed longitudinally from adolescence to early adulthood, this study tested whether relations between intelligence, academic achievement, and age at first sex were due to unmeasured…

Cognitive ability of nondiabetic children and early and late onset diabetic children was compared. Diabetic children scored in the normal range in intelligence and academic performance, but showed evidence of school difficulties and memory deficiencies. Children's perceived self-competence and parents' reports of children's functioning and…

It was concluded that age and IQ have strong influences on acquisition-retrieval, but that forgetting rate is independent of these variables. (Author)

Two studies determined the extent to which feedback could improve eighth graders' and adults' decision-making. Results showed that neither benefited from verbal feedback in choosing between easy and hard questions to earn points. Adults benefited more than adolescents from outcome feedback. Adults also benefited more than adolescents in context of…

The IQ performance of children who experienced the birth of a younger sibling was found to drop 10 points during the next two years for singleton children and 5.8 points for last-born children from families of comparable size. The study controlled for sex, family size, age at assessment, and IQ before the birth of the sibling. (Author/RH)

Although Ss underestimated the size of the illusion in the predicted direction, no significant correlations between size of illusion and either age or IQ were found. (Authors)