The Faster Sex: Examining Trial Position Effects on Reaction Time

Past research has studied the connection between reaction times (RTs) and general intelligence (IQ) in an attempt to understand individual differences in intelligence. Though general intelligence shows no gender differences, researchers have found a gender difference in reaction times. In past research, women showed slower initial choice reaction times compared to men, but became faster than men across a block of 12 trials. The present study examined whether this effect could be replicated across different RT tasks. Twenty six Ohio State University students (twelve men) participated in the study, completing four computer-based tasks: signal detection, in which the participants responded to a rectangle appearing on the screen; line-length judgment, in which the participants responded to the shorter of two lines; brightness discrimination, in which participants judged whether a pixilated rectangle appeared bright or dark; and numerosity judgment, in which participants judged whether there were many or few asterisk shown within a 10x10grid. It was hypothesized that males would outperform females during the first trial, and then females would outperform males during the remainder of the block; consequently, women would show a greater variability in RT in each task, as measured by the coefficient of variance (CV, standard deviation divided by the mean). We found a trial-by-trial effect on mean RTs for all tasks, but no trial-by-trial gender effect on mean RTs or CV across trials in any of the tasks. There was, however, a gender effect on CV across blocks in three of the tasks. These differences in results among tasks may be due to differences in the cognitive demands on each sex for each task, especially considering that sex differences are observed in a variety of tasks. This suggests that the type of tasks used can change the sex effect seen in a given RT study.No embarg