In 1518, in Strasbourg, Alsace, a group of about 400 people danced, without rest, for days on end. It became known as the 'Dancing Plague' and it continued for a month, with many of those affected by the 'epidemic' dying of heart attack, stroke and exhaustion.

Elsewhere, in 1844, in a convent in France, a nun began to meow like a cat. Then another one did, and another one. Before long, the entire convent was meowing. Neighbours in the surrounding area of the convent soon became concerned and soldiers were called in to contain the situation.

Closer to home, in Ireland, in 2014, an epidemic known as 'Garth Brooks mania' swept the country. Hundreds of thousands of Irish people, many of whom believed the country and western singer was the next messiah, were up in arms when it was announced that five of his sold-out concerts were cancelled due to planning laws.

The mass hysteria culminated in Fianna Fáil drafting new legislation known as the 'Garth Bill' to allow the concerts to go ahead. Meanwhile, a group of citizens contacted the White House and asked them to intervene.

There are all sorts of names for this herd behaviour - mass hysteria, collective insanity, emotional contagion. Whatever name you give it, it's a reminder that the society we live in influences our behaviour, just as our behaviour influences the society we live in.

Of course, we usually only see this in hindsight, or when we're surveying the wreckage. "Sure, we lost the run of ourselves", etc.

In other cases, the behaviour becomes so institutionalised that we barely notice it at all.

A friend of a friend recently slept under his office desk for two nights in a row. He was trying to meet a deadline and he reasoned that he'd have more time to complete the report he was working on if he cut out the commute and ate his Rice Krispies in the canteen.

I think we can all agree that bringing a sleeping bag to work is an act of insanity. However, its worth asking what part we have all played in creating a culture that made this gentleman think it was a stroke of inspiration.

The first meow, so to speak, was the diminishing lunch break. Nowadays most of us have mastered the art of eating a hot chicken roll with one hand while typing an email with the other.

Next came the end-of-day standoff. Only defectors put on their coats at 5.30pm. Look at them! Swanning out the door, obviously off to live their lives or something...

I know of one woman, a working mother, who calls her daily departure from the office 'the 5pm walk of shame'. She clocks in eight productive hours each day, yet she still feels guilty when she's the first to leave (even if she's often the first to arrive).

Remote email access was the deathblow. The already tenuous line between work and life blurred into one the day the IT department gave us the capacity to read work emails from under our duvets.

Compounding all this is the trivialisation of the word 'workaholic'. Workaholism is a soul-destroying, sometimes deadly, addiction. Granted, it has become the new normal, but that doesn't make it any less dangerous.

Sociologists often go looking for an outside force to explain cases of collective insanity, but they never find the trigger. The only conclusion that they can draw is that, in these cases, individual minds behave as a system.

They've also noticed that collective insanity thrives in organisational structures - schools, universities, religious congregations... In short, any social dynamic in which personal boundaries have already been attenuated (the workplace being a perfect example).

An outsider looking in would consider the cult of overwork a kind of collective insanity. The trouble is that we don't have many outsiders to provide this perspective because most of us are part of the problem. We think of the diminishing lunch break as a modern necessity and overtime as a corporate inevitability. But perhaps we've just lost our senses.

A sane-minded employee, for example, knows that breaks increase overall output, while productivity starts to dwindle when we work for 50 hours or more each week. Sane-minded employers, meanwhile, are tackling the overwork epidemic by introducing four-day weeks and five-hour days (typically, the employee works from 8am-1pm with no break).

The overwork epidemic has spread like a contagion, and the only way out is the way we went in.

It's time for a new 'office martyr' to emerge: we need employees who take an hour for lunch, leave work at 5.30pm with their heads held high and wouldn't, in a month of workdays, consider sleeping under their desk.

Weekend Magazine