General Cognitive Ability and the Psychological Refractory Period

Abstract

Identifying the precise locus of general cognitive ability ( g) in the flow of information between perception and action is an important goal of differential psychology. To localize the negative correlation between g and reaction time to a specific processing stage, we administered a speeded number-comparison task to two groups differing in average g. The participants had to respond to two stimuli in each trial, which produced the well-known slowing of the second reaction time known as the psychological refractory period. The difference in the second reaction time favoring the high- g group doubled as the stimulus onsets became very close together. This finding affirms that the faster reaction times of higher- g individuals reflect an advantage exclusively in the serial bottleneck of central processing and not in the parallel peripheral stages.