Circadian preference and intelligence – an updated meta-analysis. (3rd August 2021)

• Record Type: Journal Article
• Authors: Ujma, Péter P.; Scherrer, Vsevolod
• Is Part Of: Chronobiology international. Volume 38:Number 8(2021)
• Page Start: 1215
• Page End: 1229
• Publication Date: 2021-08-03
• Subjects: Circadian preference -- chronotype -- IQ -- cognitive ability -- meta-analysis; Chronobiology -- Periodicals; Biological rhythms -- Periodicals; Circadian rhythms -- Periodicals; 571.77
• DOI: 10.1080/07420528.2021.1926473
• Languages: English
• ISSNs: 0742-0528

Abstract

ABSTRACT: A large number of previous studies reported a link between circadian preference and psychometric intelligence with mixed results and various hypotheses about the source of this correlation. In this study, we aimed to update a previous meta-analysis about the correlation between circadian preference and intelligence. Our literature search identified a large number of new studies, resulting in an increase of over 100% in the number of studies and over 400% in the number of involved participants (total k = 30, total N = 11160) over the previous meta-analysis, sampling a much wider age range from children to adults in late middle age. Our meta-analysis revealed no significant link between morningness and intelligence (r = −0.008) when the entire sample was studied, and no evidence for publication bias. This overall effect, however, obscured the moderating effect of age. The morningness-intelligence correlation decreased with mean sample age (R 2 = 54%), ranging from a non-significant positive trend in children and adolescents to a significant negative correlation after young adulthood. Eveningness was positively correlated with intelligence (r = 0.056), but this finding is based on a more age-restricted sample and only reached significance with some model specifications. We hypothesize that the age-moderated correlation between circadian preference and intelligence reflects social effects, where more intelligent individuals are more able to adjust their daily schedules to their natural circadian rhythm.