By Edward Parker 
When it comes to going that extra mile, many people rise honourably to the challenge but, truth be told, the rest of us would rather stay in and watch Neighbours. For a long time, idleness has been associated with those who lack the motivation to do something useful with their brief existence. But now science might have another answer.

Many aspects of our behaviour on a day-to-day basis result from the intricate workings of our body’s internal clock. This extends as far as our temperature, the level of hormones in our blood, and, crucially, how alert we are. The biological clock, or “circadian rhythm”, is a self-sustaining loop that relates to the expression of particular genes throughout the day. In mammals, the main control centre for this daily rhythm lies in a part of the brain just behind the eyes, called the suprachiasmatic nuclei. Here, a range of genes is expressed in daily cycles, responding to varying light levels that influence our temporal behaviour changes. For instance, the two genes, Timeless and Period, act together to regulate a cascade of other physiological processes that govern our changing activity and temper.

Mutations in any of the numerous genes that influence our biological clock can result in this being speeded up or slowed down. In some cases, this change can be extreme. For instance, people suffering from the hereditary disorder, Familial Advanced Sleep Phase Syndrome (FASPS), wake up at around 4.30am and fall asleep at around 7.30pm. The tem oral program of behaviour and physiology is so scrambled that regular patterns of day and night are impossible to keep up with.

However, not all mutations are so extreme. Many variations of the genes influencing our biological clock only subtly alter our patterns of alertness and mood each day. In fact, it has recently been shown that the tendency of some to be “morning people” (think of the rowers who return from a dawn outing before you’ve had time to ignore your first alarm) may be in no small way related to predisposition of the biological clock.
And what about the rest of us? The genes which enable some people to pay attention during a 9am lecture are perhaps be the same ones causing the rest of us to fall asleep after five minutes. Of course, this might also be due to that late night at Filth you’re trying so hard to forget.