The Flynn effect

The Flynn effect refers to the observed pattern that average IQ scores have increased over time across many countries, roughly by three points per decade since the early 20th century. This rise is thought to result from various societal factors, including improved education, better nutrition, healthcare, and more exposure to complex problem-solving activities. The effect suggests that intelligence, as measured by IQ tests, is partly shaped by environmental influences that can change over generations, rather than being entirely fixed or hereditary.