Described is an ongoing study of monozygotic and dizygotic twins, separated in infancy and reared apart. Discussed are the procedures and results of this study with interpretations of the results. The effects of parenting, education, and other interventions are considered. (CW)

Although it is difficult to ascertain precisely the time at which the study of individual differences became recognized as a specialty within the psychological sciences, there appears to be much agreement among historians that its development was fostered primarily within the United States during the late 19th century. This paper examines the…

The futility of the debate between heredity and environment as determinants of intelligence is argued, with convictions inspired by C. Burt's work (apart from the question of fraud in his work). It is contended that the influence of this misconceived ideological disagreement is apparent in today's educational systems. (SLD)