The Flynn effect in the Czech Republic

•The Flynn effect in the Czech Republic for the last 44 years was estimated.•The Flynn effect was established at 0.23 and 0.42 IQ points annually.•The Flynn effect in the two tests used differed in accordance to the rule-dependence model.

The Flynn effect in the Czech population presented here was estimated based on the re-standardization of two short intelligence tests on a sample of 133 eighth-grade students. For over 44 years, the average performance in these tests had been improving by 0.23 and 0.42 IQ points per year respectively. There had been a significant difference between the tests at p < 0.05, although both tests had been designed to measure fluid intelligence. We propose that the gains in the test scores were generally brought about by changes in the Czech education system, while Armstrong and Woodley's (2014) rule-dependence model provides a reasonably accurate explanation for the difference between the tests.