In the journal Personality and Individual Differences is a 2009 study titled “Why night owls are more intelligent“. ABSTRACT:
The origin of values and preferences is an unresolved theoretical problem in social and behavioral sciences. The Savanna–IQ Interaction Hypothesis suggests that more intelligent individuals are more likely to acquire and espouse evolutionarily novel values and preferences than less intelligent individuals, but general intelligence has no effect on the acquisition and espousal of evolutionarily familiar values and preferences. Individuals can often choose their values and preferences even in the face of genetic predisposition. One example of such choice within genetic constraint is circadian rhythms. Survey of ethnographies of traditional societies suggests that nocturnal activities were probably rare in the ancestral environment, so the Hypothesis would predict that more intelligent individuals are more likely to be nocturnal than less intelligent individuals. The analysis of the National Longitudinal Study of Adolescent Health (Add Health) confirms the prediction.