Flynn-effekten i Norge og andre land: Praktiske implikasjoner og teoretiske spörsmål
Sammanfattning
A number of studies have documented significant gains in mean IQ scores across generations (the Flynn effect). Flynn effects have been found in more than 30 industrialized nations, including Norway, but also in developing nations in Latin America and Africa. In the current paper, we present international and Norwegian results attained from young male military conscripts, encompassing new and unpublished data. In accordance with international data, the mean IQ scores in Norway increased from test years in the late 1950s (birth cohorts ≈ 1938–1940), but with decreasing gain rates, to the mid-1990s. After the mid-1990s, increases in the means ceased and exhibited decreasing tendencies. Our new data set shows that these decreases have continued into the new millennium. Practical and methodological consequences of the secular trends in IQ scores are often overlooked. We address issues related to the use of intelligence tests in situations where decisions with potentially serious consequences for participants are involved. In particular, we underscore the need for test norms that take the Flynn effect into consideration. In cross-sectional studies, age and birth cohort are completely confounded. Effects of birth cohort on intelligence (Flynn effect) have often been wrongly interpreted as age effects. To study age effects, longitudinal studies are needed. There are several theories addressing the possible causes of the Flynn effect. In the present paper we discuss how well existing theories explain known facts, with special emphasis placed on the Norwegian data.