Abstract
A sample of 220 normal pre-school and primary school children was tested by the Continuous Performance Test(CPT), a test of sustained attention (vigilance), the Drawa-Line Slowly test (DALS), a test of motor inhibition and two sub-tests of the latter test. Significant social class associations were found for the CPT and DALS tests, but were not present for DALO and DALF (measures of speed in drawing a line). Sex differences were not found for the CPT test or for DALS, but the boys completed the DALO and DALF tests faster than the girls suggesting superior motor activity and co-ordination.