Chronotypes
Society operates on lark schedule (schools start 7:30-8:30 AM, work 8-9 AM, important meetings 9-11 AM), disadvantaging 25% of the population.
Chronotypes are genetically-determined individual differences in circadian phase. Approximately 25% of the population are 'owls' (evening chronotype) with long PER3 alleles and CRY1 delayed sleep phase variants - their cortisol surges 2 hours late (9-10 AM), melatonin onset 2 hours late, cognitive peak 4 PM-10 PM, natural wake 9-10 AM, natural bedtime 1-2 AM. Another 25% are 'larks' (morning chronotype) with short PER3 alleles - cortisol surges at 5-6 AM, cognitive peak 8 AM-12 PM. The remaining 50% are 'hummingbirds' (neutral chronotype) with intermediate alleles, peaking 10 AM-6 PM and flexible enough to adapt either direction. Forcing owls onto lark schedules causes chronic sleep deprivation and performance reduction of 20-30%.
Business Application of Chronotypes
Society operates on lark schedule (schools start 7:30-8:30 AM, work 8-9 AM, important meetings 9-11 AM), disadvantaging 25% of the population. Smart companies match tasks to chronotypes: larks for morning shifts, owls for evening/night work, critical decisions scheduled at 10 AM-12 PM when all chronotypes overlap.