Evidence from twin studies points to substantial environmental influences on intelligence, but the specifics of this influence are unclear. This study examined one developmental process that potentially causes intelligence differences: learning to read. In 1,890 twin pairs tested at 7, 9, 10, 12, and 16 years, a cross-lagged…

Discusses the patterns of mental development of 350 pairs of twins studied longitudinally from 11/2-6 years of age. (DP)

Examined consistency of hand preference in a longitudinal study of children between 18 and 42 months of age. Results showed a sex-specific relationship between hand consistence and intellectual development. Females with consistency of handedness were precocious compared to females without such consistency; the same relationship did not hold for…

Examined the origins of high general cognitive ability (g) in twins who were participating in the MacArthur Longitudinal Twin Study. Formed high g groups from the 19th percentile and above at each age. Results suggested increasing genetic influence and increasing genetic stability from 14 to 36 months and substantial genetic influences with…

Women who won National Merit Scholarships during the years 1956 through 1960 were followed up in 1965 to determine their marriage and/or career plans. Each of the 883 women was classified into one of five groups: (1) marriage only, (2) marriage with deferred career, (3) marriage with immediate career, (4) career only, and (5) uncertain. The…

Selective subject attrition from longitudinal study panels can bias estimates of developmental change. Particularly in studies of older adults, sampling effects can adversely affect attempts to estimate true ontogenetic change. Selective attrition effects were examined in 636 Pennsylvania adults (138 males, 498 females), aged 58-91, who were…

Examined influences on African-American children's cognitive development between 6 months and 8 years. Found that more optimal patterns of development were associated with intensive early educational child care, responsive home stimulation, and higher maternal IQ. Child care experiences were related to cognitive performance through enhancing…

This book describes the Reflective Judgment Model (RJM) and provides a comprehensive review of the research on it and the Reflective Judgment Interview (RJI). Chapter 1 defines reflective judgment as an often neglected aspect of critical thinking. Chapter 2 discusses stage-related assumptions that underlie RJM and relates RJM to current work in…

A total of 125 white children from three counties in Georgia (selected as representative of small rural and medium and large industrial urban populations) were administered a battery of tests in three phases of their schooling: (1) during the summer preceding their admission to the first grade, (2) near the end of the first grade, and (3) near the…