Genes, body clocks and prevention of sleep problems.

Chronobiologists argue that their scientific findings have implications for prevention of sleep problems. They claim that some sleep problems are caused by the fact that people live against their individual body clock rather than adjusted to it. They also claim that by taking the findings of chronobiology seriously in policy-making some sleep problems can be prevented. I investigate applications of chronobiology in two social areas-school schedules and shift work-and show that in order for these applications to be justified certain implicit presumptions have to be justified. The first presumption is explanatory, namely that a chronobiological explanation is an adequate explanation of the sleep problems at hand. In addition I analyse three ethical presumptions. The first ethical presumption is that sleep is of vital value. The second is that sleep is not an exclusively private issue. The third ethical presumption is that the preventive measures to be undertaken are ethically acceptable. My main point is that it is not possible to simply "read off" policy measures from the empirical findings of chronobiology.