Twenty years a growing: gains in the intelligence test scores of Irish children over two decades

Using data from Gill and Byrt's 1972 standardization of the Ravens Standard Progressive Matrices (RSPM) on a national sample of Irish primary school children, O'Connor & Ruddle's 1987 survey of a large sample of school children in Clare and Jeffer's and Fitzgerald's 1989 survey of 9-12 year olds in a Dublin suburb, we found that over the period from 1972-1989 the mean gain in IQ points on the RSPM was approximately 9 IQ points. This gain of about 0.6 standard deviations in IQ points has occurred in both a rural and an urban area. The 9 IQ point gain over about 16 years is comparable to the 18 IQ point gain that has been observed on culture reduced tests over the 30 year period between 1950-1980 in 14 of the world's advanced economies.