The role of intelligence in the distribution of national happiness

We study the relationship between intelligence (IQ) and happiness inequality, measured by the standard deviation of life satisfaction, in a cross section of 81 countries. We find that higher levels of IQ are significantly correlated with lower levels of happiness inequality. This relationship is highly statistically significant even when we control for the level of economic development and a large set of control variables including economic freedom and social capital. We furthermore find suggestive evidence that economic development has a happiness equalizing effect, but this effect is, at least partially, mediated by the level of intelligence. Nations with higher levels of economic development and low IQ tend to experience less equal distribution of happiness compared to nations with higher levels of economic development and high IQ. The results are robust for a panel of 50 US states from 1972 to 2012 that uses alternative measure of intelligence from the US General Social Survey.