Are Human IQs Falling?

The Flynn Effect and why it may be reversing

J.K. Lund MS

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Human IQs were rising globally in the 20th Century, but now some scientists think they are beginning to fall. The rising trend of IQs, known as the Flynn Effect, states that each generation will, on average, score higher on IQ tests than the last. But as we enter the 21st Century, the Flynn effect may be stalling, if not beginning to reverse itself. What does this mean for the future of humanity and progress?

What is the Flynn Effect?

The “Flynn Effect” is an observed rise in intelligence test scores, first documented by researcher and philosopher James Robert Flynn in 1984. Flynn’s initial study calculated an average 13.8-point increase in IQ scores between 1932 and 1978, or about 3 points per decade. While the causes and reasons for the Flynn Effect are the subject of much debate, it is generally accepted that globally, humans scored higher on standardized IQ tests with each passing generation.

For example, if we tested the IQ of a sample of Baby Boomers when they were 20 years old and compared those results to the same test also administered to Millennials at the age of 20, we would expect the latter group’s average IQ scores to be higher. To be clear, none of this is to suggest that younger people are necessarily smarter, but more precisely, that they are scoring better on various standardized tests that measure IQ.

Dozens of subsequent studies have confirmed the Flynn Effect. New calculations of IQ score gains, made between 1972 and 2006, using different versions of the Wechsler Adult Intelligence Scale, Stanford-Binet, and Wechsler Intelligence Scale for Children, indicate an IQ increase of about 0.31 points per year. This finding is broadly consistent with Flynn’s findings in the 1980s.

What Causes the Flynn Effect?

There are multiple proposed causes of the Flynn Effect. Mingroni (2007) hypothesized that…

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J.K. Lund MS

Risk Manager/Author | I research Human Progress and how to build a better future.