You wake up to an alarm that’s too loud, scrape yourself out of bed and look out of the window only to see chirpy people who have been up for hours jogging, or walking the dog.  Or the opposite; you wake up at 7am sharp every morning feeling fine and feel frustrated that your partner is snoozing and would get in a grump if you interrupted.

Why are we all so different?  And why can’t we all just get along?

The myth is that everybody should be able to take control of their sleeping habits.  Morning people get annoyed with oversnoozers, saying that if they went to bed on time and got enough sleep they would be fine.  And late people get annoyed with early birds for forcing their sleep patterns onto everyone else, even when they don’t fit.   The reality is there is a little truth in both of these.  You can exhaust yourself and move your sleep pattern earlier or later as you choose to.  It’s not fun and involves keeping yourself awake so that you are ready to sleep at an unnatural time.  But even if you succeed in doing this, as many people need to for work, this will probably not make you a chirpy morning person.  There is something in your system that dictates when the day starts, and it’s probably the most simple and obvious reason.

The Earth spins and has its regular days and nights and seasons.  But our bodies aren’t necessarily linked to this as even astronauts have a sleep cycle.  Let’s start at the beginning.

What time were you born?  Your life starts when you enter the world, and what happens next shapes your timekeeping for the rest of your life.  Babies with daytime births are generally kept awake to be shown off to family for a bit, but if it’s late at night or the labour was particularly exhausting then sometimes mother and baby just go to sleep until the following day.  Your cycle will start with either a waking-up time or a sleep time, depending on which of these happens.  So if you were born at 11am and kept up, you’ll probably be fond of your snooze button and wake up just in time for lunch.  Born at 7am, you’ll likely be part of the GMTV and The Big Breakfast generation.  Born at 3am and put to sleep?  I’ll bet you’ve spent a lot of insomniac time at the keyboard illuminated only by your screen, and crash out in the early hours.  And the people who always need to have a snooze after dinner were born and tucked in for a nap during the late afternoon.