Most of us need an alarm clock to ensure that we get up on time all the time. However, there are some folk out there who seem to have a natural, in built alarm clock. They are able to wake up at the same time every morning. This natural alarm clock is believed to be the result of a burst of a stress hormone called andrenocorticotropin.
Many researchers think that the reason these people have this burst of andrenocorticotropin is because of the unconscious anticipation of the stress of waking up. This would suggest that it is a particular personality type that is has the natural alarm clock function installed.
Whatever the cause, it can be a very useful ability most of the time, but for many of the people who have this ability it can also be a bane, usually in the weekend when they don’t have to get up, yet they still get this sudden hormonal burst that knocks them out of their blissful Sunday morning sleep in way too early.
Also, despite it being reasonably reliable, it is not as reliable as an alarm clock and it is hard to imagine a boss who would let you away with saying your ‘natural alarm clock’ failed to wake you up.