Sorry I'm late, it's all down to my chronobiology

Individuals differ in terms of their chronotype – that is to say whether you are morning oriented or evening oriented, or somewhere…

Individuals differ in terms of their chronotype – that is to say whether you are morning oriented or evening oriented, or somewhere in the middle

We are well into party season as the holidays approach, with dinners, drinks with friends and similar festive cheer. But in the midst of all the fun there is also an annoyance: the latecomer.

Everyone knows someone who is always late. Maybe you’re one of those people yourself. Theories on why some individuals are late on a regular basis come from a variety of perspectives – anthropological, cultural, neurological and psychological. But are there scientific explanations for chronic lateness?

We are all governed by our circadian clocks. The study of this internal clock comes under the heading of chronobiology. “Circadian rhythms are internal 24-hour rhythms created by the Earth spinning on its axis within a 24-hour period,” says Dr Andrew Coogan, a chronobiologist at NUI Maynooth.


“Life has evolved to take advantage of that. Through evolution we have adapted a time-keeping mechanism. Animals and organisms can anticipate changes in their environment and then react appropriately. It’s important particularly for preyed-upon animals, who know to get home before it’s dark.”

The existence of circadian rhythms was first demonstrated in the 1960s when human subjects were placed into a timeless environment – a concealed former second World War bunker to be exact – with no time-reference points, clocks, natural light and so on.

It was found that the volunteers still expressed 24-hour rhythms through their internal clock. They had energy at appropriate times, slept at night time and were awake during the day.

But circadian rhythms affect individuals differently and can lead to inclinations towards “morningness” or “eveningness” and, in turn, “lateness”.

“Individuals differ in terms of their chronotype – that is to say whether you are morning oriented or evening oriented, or somewhere in the middle,” says Coogan.

“This is both an individual characteristic but also changes across the lifespan so small children generally are morning oriented, teenagers tend towards eveningness, then back towards the morning in adulthood.

“This affects the time of day we are most alert and our cognitive prowess is best set up for. Such individual differences seem to be down in part to genetics, but may also be driven by environmental factors – TVs, computers in bedrooms and street lighting at night might all make for a tendency toward ‘eveningness’.

“It might also explain in part lateness. If you are trying to get out of bed and get to school early yet your body clock is not attuned to that rhythm you may struggle and end up being late. So some of us may be predisposed to be late at different times of the day – probably most pertinent to the morning.”

The inclination towards morningness and eveningness also relates to personality. Eveningness tends to be associated with creativity and impulsiveness.

“Plus if you’re a strongly creative person you lose a sense of time when you’re in the middle of something you find very interesting – otherwise known as the absent-minded professor effect,” says Billy O’Connor, professor of physiology in the Graduate Entry Medical School in the University of Limerick.

“People get so engrossed in what they’re doing, they lose any sense of time. It’s actually a sign of good mental health. But it can be very frustrating for other people.”

Morning people, on the other hand, tend more towards conscientiousness and better organisational skills.

“Some people are future oriented so time is very important to them,” says Coogan. “Those who live in the present are not so bothered with being late.”

Being late for a flight or an important meeting is stressful and some people get addicted to that feeling. “Creating a stressful environment can be used by people to up their game,” says O’Connor. “It helps some people focus but you can become addicted to stress, more specifically the hormone cortisol. Its release gets you whizzing along when you need it most.

“Chronic stress ages the body and the brain. So this kind of behaviour works in the short term and does help some people get more done in their lives. But the brain performs optimally when it is calm and focused.”

There is, of course, one other reason why 3pm means 3.30pm to some people. “It can be a power thing,” says O’Connor. “In a business meeting setting, for example, which is a complex social gathering with multiple agendas and strict rules of engagement. They are not casual affairs so being constantly late for a meeting without a valid reason may be regarded as discourteous in a group.

“It may also be regarded as attention seeking, selfish behaviour and signs of a disorganised mind, and will more than likely result in social exclusion,” he says.

Daydreaming in the ‘default network’

Do you daydream? Actually, we all do and researchers have pinpointed the area of the brain that lets you daydream.

This “default network” in the brain involves three areas – the frontal lobe, parietal lobe and temporal lobe. Recent research suggests this area is switched on when we daydream.

Yet the moment we are asked to do something, the circuit switches off and we are back in the present.

“The default network is where we travel in time, where we think about the future or look into the past,” says Prof Billy O’Connor of the University of Limerick.

The phenomenon of the default network was discovered by medical staff performing brain scans on people. This default network can be damaged in those who have suffered strokes, Alzheimer’s Disease or other brain-related conditions.

“What happens is that people are stuck in the ‘now’, and are no longer able to go back to the past or think about the future,” says OConnor. “They become trapped in the present because the default network has been knocked out. We refer to this as ‘endless now’.”