Study finds a link between chronotype and shift worker's sleep Getting enough sleep can be a real challenge for shift workers affecting their overall health. But what role does being an early bird or night owl play in getting good rest? Researchers from McGill University find a link between chronotype and amount of sleep shift workers can get with their irregular schedules. Some people seem to be hardwired to sleep early, while others tend to sleep late. This preference, called chronotype, is modulated by our circadian system - each person's unique internal timekeeper." Diane B. Boivin, Lead Author, Professor, Department of Psychiatry, McGill University