Around their 18th birthday basically all dutch males born between 1934 and 1964 unknowingly took part in a study of the malleability of intelligence when these young men appeared before the dutch military draft board they took a non verbal iq test based on ravens 1960 progressive matrices with a little help from piet vroon james flynn 1987 discovered that those born in 1934 cohort . This proposed process is similar to the flynn effect where the iq tests are being improved over the years in the flynn effect in order to sustain the mean value stabilized the relevant iq tests. The flynn effect refers to the massive increase in iq test scores over the course of the . The flynn effect denotes the continuous increase in intelligence test scores over time at the population level flynn 2007 it was first noted in scotland when comparing group iq test results on