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;…

Presents a study of a theoretical confluence model which predicts the effects of birth order, child spacing and family size on intellectual development. The fit of this model was tested on samples of families with biological and adopted children. (JMB)

Analyzed genetic and environmental contributions to intellectual change in 258 adopted and 93 biological children of 3-14 years. The effect of genes and family environment was significant at the time of the first measurement, but only genes made an additional contribution between the first and the second. (RJC)

Examined relations among measures of child language derived from observations of 20-month-olds' speech with mothers, experimenter assessments, and maternal reports. Found that structural equation modeling supported strong relations among the three sources, the loading of multiple measures on a single latent construct of vocabulary competence, and…

Studied the extent to which memory and processing speed accounted for relations between infant information processing and childhood IQ. Found that the relationship of 7-month visual recognition memory and 1-year cross-modal transfer to 11-year IQ were reduced when statistically controlled for factors derived from these measures, suggesting that…