In complex three-dimensional mental rotation tasks males have been reported to score up to one standard deviation higher than females. However, this effect size estimate could be compromised by the presence of gender bias at the item level, which calls the validity of purely quantitative performance comparisons into question. We hypothesized that…

Eighty-one university students were given a battery of reaction time tests and a group test of intelligence which yielded timed and untimed scores. Multiple regression analyses indicated that speed of information-processing was an equally good predictor of timed and untimed intelligence test performance. (Author/LMO)

Three hypotheses accounting for individual differences in spatial visualization ability were investigated in 2 experiments with 142 male undergraduates at Georgia Institute of Technology (Atlanta). Support was found for the preservation-under-transformation hypothesis, suggesting that effectiveness of storage during concurrent information…

According to mental speed theory of intelligence, the speed of information processing constitutes an important basis for cognitive abilities. However, the question, how mental speed relates to real world criteria, like school, academic, or job performance, is still unanswered. The aim of the study is to test an indirect speed-factor model in…

Mental-rotation task response times from 12 studies involving 505 adults--251 males and 254 females--were used to evaluate 5 hypotheses concerning sex differences derived from an X-linked genetic model. The model assumes that task facilitation in speed of mental rotation is mediated by a recessive gene. Four hypotheses derived from the model were…

The working memory hypothesis that the development of span in children is related to increasing proficiency in the use of an articulatory loop was tested in two studies with 120 Canadian children in grades 5 and 6 and 11 and 12. Some support was found for the hypothesis. (SLD)