An estimate of the Flynn Effect: changes in IQ and subtest gains of 10-yr-old French children between 1965 and 1988.

The significant increase in IQ in the industrialised countries during recent decades, known as the eponymous Flynn Effect, tends to be given numerous explanations (progress in schooling, television, nutrition, etc.). One way of studying this effect consists of assessing in which subtests the change in IQ takes place. Using the comparison among 120,000 French children on an intelligence test in 1965 and the results of 8640 children on the same test in 1988, Greenfield's hypothesis is discussed: that television and other media using graphical representations have induced an improvement in spatial and visual capacities to the detriment of capacities relating to vocabulary. The results are compatible with Greenfield's hypothesis, although other explanations are still possible.