What is the Flynn effect?

The Flynn effect refers to the observed phenomenon that average IQ scores have been increasing over time across generations. This trend suggests that each subsequent generation tends to score higher on intelligence tests than the previous one, a trend that has been documented in many countries since the early to mid-20th century.

Several theories have been proposed to explain the Flynn effect, including improvements in education, better nutrition, and more complex environments encountered by children today compared to the past. These factors contribute to cognitive development, leading to higher performance on IQ tests over generations. The recognition of the Flynn effect has important implications for how we understand intelligence and the impact of societal changes on cognitive abilities.

In contrast, the other options do not align with the Flynn effect. Decreasing IQ scores over time would indicate a decline in intelligence, which is contrary to this concept. Stable IQ scores would imply no significant change across generations, which does not reflect the empirical evidence of rising scores. Variation in test scores due to cultural factors speaks to the influence of different environmental and contextual factors on intelligence but does not capture the overarching upward trend in scores outlined by the Flynn effect. Thus, the increasing IQ scores over time is the defining characteristic of this phenomenon.