A Cross-Temporal Meta-Analysis of Ravenʹs Progressive Matrices: Age groups and developing versus developed countries

While many studies have investigated the rise in IQ over time in various countries, the present study attempts to fill the gap in the Flynn effect literature by considering data with various sample sizes, and different study designs, age groups and types of country. A Cross-Temporal Meta-Analysis (CTMA) technique was used to examine the relationship between mean IQ scores from the Ravenʹs Progressive Matrices (RPM) and years of publication, moderated by age group and types of country over a period of 64 years (1950–2014). In all, 202,468 participants were included from 48 countries. We conclude that there is an obvious link between mean IQ scores and years of publication. Importantly, interaction analyses indicate that both age group and types of country moderate this relationship.