I am a biologist and am engaged in research on the little-understood phenomenon of waking before alarms. This is a recent video I made on the subject https://www.youtube.com/watch?v=1tUO0gDFk5Q&t=29s
Recent surveys have shown that more than 90 per cent of the population have experienced shortly before an alarm clock goes off. This is not just a matter of routine and habit, because most people have also found that they wake before alarms at unusual times, for example at 4.30 am to catch an early flight.
In the past, when most people used mechanical alarm clocks, this might have been explained by a clicking sound before the alarm went off. But nowadays most people have electronic alarm clocks or use phones where there is no sound beforehand.
Some people find that they do not even need the alarm clock. They can tell themselves to wake up at a particular time and then wake just before that time.
The most obvious explanation would be in terms of an unconscious time sense. Humans, like many other species, do indeed have built-in biological rhythms. But generally these are only approximate. And in rural societies, in which most of our ancestors lived, there was no need for waking at precise times. There were no early flights to catch, and most people did not have watches or clocks anyway. Waking with the cockcrow was good enough. It is unlikely that a very precise time sense during sleep would have evolved under these conditions.

But there is another possibility. Recent research at the Institute of Noetic Sciences in California and Cornell University has shown that people can react physiologically before an emotionally arousing stimulus. They somehow feel the future. Could this play a part in waking before alarms?
The best test for this possibility is when people wake before unexpected disturbances. If there is an explosion nearby in the night, for example, or if a fire alarm goes off, do some people still wake shortly beforehand?
In a recent appeal for information on the subject a fireman in Australia told me, “Whenever the alarm would go off in the night I would regularly wake up 5 to 10 seconds before the siren would sound. It was uncanny. I would regularly sit up and put my feet on the floor just as the alarm would start to sound.”
For most people being woken by an unscheduled alarm or siren is an unusual experience. But for firefighters and others in emergency services, it must be more common.
If you have had this experience of waking soon before unscheduled alarms or sirens, I would be happy to hear about your experiences. Please email me at sheldrake@sheldrake.org
Dr Rupert Sheldrake is a biologist and author of several books, including Dogs That Know When Their Owners Are Coming Home.
For more information, go to www.sheldrake.org