At a discussion of the social implications of our 24/7 society, held at the Science Museum's Dana Centre tomorrow, Prof Till Roenneberg of Ludwig Maximilians University, Munich, will describe how he has discovered that people have a "chronotype" which influences their health and profession.
Roger Highfield, "Researchers shed some light on owls and larks of the workplace," The Daily Telegraph, March 29, 2004
A morning-type individual, or "lark", is defined as one whose circadian rhythms are skewed about two hours (or more) earlier than the norm for the human population as a whole. That is, larks naturally awaken between 4:00 a.m. and 6:00 a.m. and are ready for sleep by 8:00 p.m. to 10:00 p.m. To a lark, midnight is perceived as the middle of the night. Conversely, an evening-type individual, or "owl", is defined as one whose circadian rhythms are skewed about two hours (or more) later than the norm for the population. That is, owls naturally awaken between 8:00 a.m. and 10:00 a.m. and do not find themselves feeling sleepy until the midnight-to-2:00 a.m. time frame.
"Chronotype Test," Round-the-Clock Systems, 1999
A sample of 537 subjects aged 21 to 30 completed questionnaires on personality, preference for time of day and consumption habits.
They were classified according to "chronotype" (morning, evening or neither).
"'Evening people' drink, smoke more," Journal of the Addiction Research Foundation, August, 1994
If you'd like to find out where you fit on the lark-owl spectrum (I'm a Moderate Lark), take this test.