Night vs Morning people - Star Trek: Website

Morning people, in my experience at least, firmly believe that night people are just morning people with insufficient self-discipline.
There’s actually a genetic bias on it. It can be overridden, but you’ll always feel a bit burnt out from it. It also changes with age (teenagers are the latest, getting earlier as you age.
Genetic Basis of Chronotype in Humans: Insights From Three Landmark GWAS

Chronotype, or diurnal preference, refers to behavioral manifestations of the endogenous circadian system that governs preferred timing of sleep and wake. As variations in circadian timing and system perturbations are linked to disease development, the ...

PubMed Central (PMC)