Individual differences in performance on 4 computer-controlled visual memory and recognition tasks as a function of performance on 5 paper-and-pencil spatial tests were studied for 90 psychology students attending the University of Rennes (France). Results show that spatial thinking is partially supported by visual memory. (SLD)

Intellectual abilities were measured for 217 German and 205 American college students using tests (in the subjects' native languages) in which equivalence was established by an item-response theory-based differential-item-functioning (DIF) analysis. Comparisons between groups were not the same before and after removal of DIF items. (SLD)

Forty-eight male and 54 female left-handed junior college students in Stockholm were grouped according to familial sinistrality and strength of handedness. Performance on computerized reaction time (RT), maze, and verbal ability tests was assessed. Sex was the only factor differentiating left-handers on RT, and no factors affected verbal ability.…

A comparison was made of ability and achievement test results and school grades for 323 pairs of Swedish male and female twins and 740 controls in relation to social background. An interaction effect of sex and social background was found for verbal ability and mathematics test results. (SLD)