Research

Hormonal

Genetic variants associated with morningness (chronotype) and sleep duration are located near genes regulating circadian rhythms (RGS16, PER2) and photoreception (INADL, HTR6), indicating a biological basis for individual differences in sleep timing.

Your tendency to be a 'morning lark' or 'night owl' is largely determined by your genetics, specifically genes like RGS16 and PER2 that regulate your internal clock. Instead of fighting this predisposition, try to align your work and sleep schedules with your natural chronotype to improve sleep quality and metabolic health.

StrongSupportsVERY_HIGH confidence
The chronotype-associated variants occur near genes known to be important in photoreception and circadian rhythms... The variant most strongly associated with chronotype... occurs near RGS16... Another signal occurs near PER2... INADL... encodes a protein that has been thought to be important in organising and maintaining the 'intrinsically photosensitive retinal ganglion cells', cells that are known to communicate directly with the suprachiasmatic nucleus
Samuel E. Jones et al. · PLoS Genetics · 2016

Why this rating

Large-scale GWAS (N=128,266) with replication in independent cohorts (23andMe, Chronogen, ICE) provides very high statistical power and robustness.

Source

Genome-Wide Association Analyses in 128,266 Individuals Identifies New Morningness and Sleep Duration Loci

Samuel E. Jones et al. · PLoS Genetics · 2016

DOI 10.1371/journal.pgen.1006125

cohort · n=128266Cited 411×
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DOI resolved against Crossref · corpus check 2026-06-10

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