PEOPLE who take up smoking may do so because they are getting up too early. That’s just one symptom of a permanently misaligned body clock, a condition dubbed “social jetlag” that could affect more than half of us.
Till Roenneberg at Ludwig Maximilians University in Munich and his colleagues used questionnaires to assess the “chronotype” of more than 500 volunteers – a measure of how much of a night owl or early bird you are. As with previous large studies, they found that the average person prefers to sleep between 12.30 am and 8.30 am, although chronotypes vary so widely…
