The Flynn effect puzzle: A 30-year examination from the right tail of the ability distribution provides some missing pieces

The Flynn effect is the rise in IQ scores across the last eighty or more years documented in the general distribution of both industrialized and developing nations primarily on tests that require problem solving and non-verbal reasoning. However, whether the effect extends to the right tail (i.e., the top 5% of ability) remains unknown. The present study uses roughly 1.7 million scores of 7th-grade students on the SAT and ACT as well as scores of 5th- and 6th-grade students on the EXPLORE from 1981 to 2010 to investigate whether the effect operates in the right tail. The effect was found in the top 5% at a rate similar to the general distribution, providing evidence for the first time that the entire curve is likely increasing at a constant rate. The effect was also found for females as well as males, appears to still be continuing, is primarily concentrated on the mathematics subtests of the SAT, ACT, and EXPLORE, and operates similarly for both 5th and 6th as well as 7th graders in the right tail. These findings help clarify the nature of the effect and may suggest ways that potential causes can now be more meaningfully offered and evaluated.

► We examined whether the Flynn effect extends to the top 5% of ability.
► The effect was found in the top 5% at a rate similar to the general distribution.
► This shows for the first time that the entire curve is likely increasing.
► The effect was concentrated on the mathematics subtests.
► The effect was the same for both sexes and appears to continuing.