nominally significantP < 0.05
We found a significant association between diurnal preference and a polymorphism in period homologue 3 ( PER3 ) ( P < 0.005, recessive model) and a novel nominally significant association between diurnal preference and a polymorphism in aryl hydrocarbon receptor nuclear translocator-like 2 ( ARNTL2 ) (P < 0.05, additive model).