BLACK-WHITE DIFFERENCES IN REACTION TIMES AND INTELLIGENCE

350 black South African 9-year-old children were compared with 239 white British children on the Standard Progressive Matrices and 12 reaction time tests giving measures of decision times, movement times and variabilities in tasks of varying complexity. The black children obtained a mean IQ of approximately 65. They also had slower decision times and greater variabilities than the white children, but they had faster movement times. The magnitude of the white advantage on decision times was 0.68 of a standard deviation, about one-third of the white advantage on the Progressive Matrices. The result suggests that around one-third of the white advantage on intelligence tests may lie in faster information processing capacity.