All those who claim to be “evening people” and find it hard to function effectively before midday now have some scientific research to back them up. A paper co-authored by Dr Stefan Volk, senior lecturer at the University of Sydney Business School, asserts that variances in our circadian rhythms mean the attention span and cognitive abilities of individuals peak at different times during a 24-hour period.

What’s more, these rhythms are linked to our genetic make-up, so someone who is more alert from the afternoon onwards can’t expect to become a morning person and vice versa.

Therefore, Volk advises employers to take account of the most productive times of individual members of staff in order to maximise overall output and efficiency. He also argues that units will operate more effectively if the cognitive peaks and troughs of proposed team members complement each other.

Circadian rhythm is a term used to describe the internal clock governing many bodily functions such as temperature and the release of melatonin. The usual thinking is that exposure to daylight governs such rhythms and that we can change them by, for instance, getting up early and opening the curtains. But Volk says that is only part of the story and research into the subject is continuing.

Light does play a part, but our genes also exert some control, meaning we can’t consciously change our circadian rhythms even if we want to. Volk’s research pays particular attention to our ability to focus at different times of the day.

“Circadian rhythms have an effect on people’s cognitive energy, as well as their physical energy,” he says. “The rhythms go up and down a lot, but there is essentially a peak and a low during the day. During the peaks, you are physically energetic and very attentive. During the lows, it’s the opposite.”

The times of daily peaks and lows vary significantly between individuals and are part of a 24-hour continuum. The rhythms also change with age

“Children are morning types, but as teenagers, they become evening types,” he says. “That’s why teenagers find it difficult to get up for school.”

From the age of 20 on, people divide into either morning or evening types. And, from 50 onwards, the majority become morning people.

Knowing this, Volk says, will help managers to build more effective teams. For example, if dealing with anything from a surgical team to a sports team or an orchestra, it’s clearly best to have people peaking simultaneously, so they are all fully focused on the task at hand. The worst scenario would be to have a group of morning people required to be at their best in the evening, a situation which in principle can be avoided.

However, certain tasks and projects clearly benefit from a spread of peaks and lows among the team.

“Take a team of three pilots working a 15-hour flight,” Volk says. “You don’t want them all peaking in the first five hours, and all feeling sleepy for the remaining 10 hours. It would be best to have one peak in the first five hours, one in the second five hours, and one in the third.”

Various tools are available to assess and understand an individual’s peak and low times. These include questionnaires, biological tests and self-knowledge.

“Most people have a good idea of their rhythms if you ask them what time they wake up at the weekend without an alarm,” Volk says. “You can also track a person’s body temperature and melatonin secretions. The end result is a point value.”

In the workplace, most employees are still part of a rigid nine-to-five scheme, but can usually say at what times they work best.

“If they don’t have to interact a lot with others, it is a good idea to let them choose what time they work each day,” Volk says. “That way, they will feel better and be more effective.”

Productivity suffers if people are out of sync, he adds. So, if an evening person has to start work at 7am and then goes home at 4 or 5pm, this can lead to a lot of unproductive time at an individual level.

Scientists are still trying to unravel all the mysteries of what makes morning and evening people different and why.

“It’s like asking why people have blue or green eyes - it’s a genetic trait,” Volk says. “Somehow, it must be evolutionary, but it’s not easy to explain. And if you try to change, you will be in a constant battle with your own nature.”

This article appeared in the Classified Post print edition as Morning or evening?