Night owls—people whose natural body clock, or chronotype, skews to late sleep and wake times—are already forced to wake up too early for office jobs and to deal with derision from early birds. And now comes a new affront: research concluding that they appear to decline faster, cognitively, than morning people.
To look into this, dementia researcher Ana Wenzler at the University of Groningen in the Netherlands analyzed sleep-based questionnaires through a large national study, BIRD-NL Project. She was able to determine people’s chronotypes and found that 52% were morning people, 44% intermediate, and only about 5% night owls—different from the general global population breakdown, where typically 30% are night owls, 40% early birds, and the rest in between.
