Chronotype correlates with developmental index, intelligence and academic achievement: A study based on nationwide indicators.

Chronotype or morningness-eveningness (M/E) is an individual trait with a biological basis. In this study, I analysed the relationship between M/E and nationwide available data, such as economic variables, school achievement, intelligence and conscientiousness, which is a personality trait. These variables have been chosen because, first, they are linked on the individual level with circadian preference, and, second these associations have been found based on meta-analyses, which gives these findings a high plausibility. In addition, economic status has also been proposed to be related to M/E. Higher developed countries showed a lower morningness, based on both, the ranking of countries as well as on the HDI value. Similarly, GNI was related to morningness, while higher intelligence and performance in PISA were related to eveningness. Conscientiousness was related to morningness, although the results failed the significance level marginally. When using IQ as a control variable in partial correlations, the relationship between GNI and morningness disappeared, as did the correlation between eveningness and PISA results.