The present experiment was designed to study the performance of boys and girls of VII, IX and XI grades on the verbal (Hundal, 1962) and performance (Bhatia, 1950) tests of intelligence. 540 boys and girls in equal proportion provided the data. Analysis of the result showed that (i) the performance of girls was significantly superior to that of boys on the "performance tests", (ii) the differentiation of mental abilities started later than it did in case of boys. The later finding is in contrast with the earlier findings from the West. The difference is attributed to the nature of tests used and some cultural characteristic of the population from which samples were drawn.