Antiquity

Classical antiquity — the period that saw the original Olympic Games and the first of Homer’s epic poems — began in the eighth century BCE. During this time, the global population was an estimated 50 million to 100 million. By 1 CE, the estimated population was at least 170 million. A significant chunk of this population was soon controlled by Rome. The Roman Empire reached its height in 117 CE, comprising all the land from Western Europe to the Middle East, with a total population between 50 million and 90 million people. 

Middle Ages

The Middle Ages, or medieval period, lasted from around 500 CE to 1500 CE, from the fall of the Western Roman Empire to the beginning of the Renaissance era in Europe. The greatest growth occurred in Europe during the high Middle Ages, when developments in agriculture, the rise of cities, and a decrease in invasions helped the population swell from 35 million to 80 million between 1000 CE and 1347 CE. Then disaster struck. Between 1347 and 1351, the “Black Death” (bubonic plague) ravaged the continent, killing some 20 million people — at least 30% of Europe’s entire population. It took until the 16th century for the population of Western Europe to once again reach pre-1347 levels. 

Globally, the worldwide population during the medieval period is estimated to have been at least 190 million in 500 CE, rising to around 425 million by 1500 CE. One of the greatest dents in the global population outside of Europe was caused by the Mongol invasion of China. Beginning in the early 13th century under the command of Genghis Khan, the war led to the deaths of tens of millions of people — at the time, the global population was around 360 million.

Renaissance Era

The Renaissance period in Europe spanned from the 15th century to the early 17th century, and can be seen as the transition from the Middle Ages to modernity in the West. The era saw a demographic shift as European powers colonized much of the Americas. Trade routes and colonies were founded, and nations began to engage in empire building. The worldwide population grew from around 350 million in 1400 to about 545 million in 1600 — a significant amount, but nothing compared to what was to come next.  

The Industrial Revolution 

The Industrial Revolution changed nearly every aspect of human society. Previously, birth rates and death rates were both very high, keeping the global human population comparatively stable. But when the Industrial Revolution began around 1760, improvements in technology, agriculture, medicine, and sanitation brought about a massive population growth spurt. In Western Europe, with people living longer and infant mortality on the decline, the population doubled during the 18th century from around 100 million to almost 200 million, and doubled again in the 19th century to roughly 400 million. Globally, a population landmark was reached in 1804 when the number of humans on Earth reached 1 billion for the first time.  

Today — and Beyond

It took many thousands of years for the human population to reach 1 billion. But once that figure was reached, the growth rate became mind-boggling — and a source of concern due to the potential overpopulation of our planet. By 1950, the global population reached an estimated 2.5 billion. Today, the number of humans stands at a staggering 8 billion — and is currently growing by more than 200,000 people each day. According to the United Nations, the global population is expected to increase by nearly 2 billion in the next 30 years, and could peak at around 10.4 billion in the mid-2080s.

Salem Witch Trials

Between February 1692 and May 1693, more than 200 innocent people were accused of practicing witchcraft in the colonial town of Salem, Massachusetts. These accusations gave way to a mass hysterical event known today as the Salem Witch Trials, which was caused by a combination of xenophobia, religious extremism, and sexism. 

The paranoia began at the house of Puritan minister Samuel Parris, whose 9-year-old daughter, Betty, along with her 11-year-old cousin, Abigail, began making unintelligible noises and convulsing. Other girls in town began exhibiting similar symptoms, claiming that it may have had something to do with being pinched and pricked by various residents who were seen to be of ill repute due to discrimination. This led to several women being accused of practicing witchcraft, including a beggar named Sarah Good, an elderly impoverished woman named Sarah Osburn, and an enslaved Indigenous woman named Tituba. While Good and Osburn maintained innocence, Tituba “confessed” to serving the devil. This confession was likely untrue and only made to avoid further punishment, but it emboldened the town to pursue further accusations. 

As mass hysteria swept across Salem, dozens of women were brought before panels and tribunals for questioning, and 19 people were executed. The courts were only disbanded after the wife of Governor William Phips was accused of witchcraft, as it was Phips who had established the courts to begin with. 

The Hammersmith Ghost 

In December 1803, a great panic struck the community of Hammersmith, a small town just outside London. Multiple locals claimed that a ghost cloaked in a white shroud had been confronting and terrorizing residents, and it was said that the ghostly specter would appear right as the church bell struck one in the morning. Locals believed the spirit was that of a villager who had died by suicide the year before, and that his tortured soul was destined to haunt the town. Residents cowered in fear at the idea of this apparition; there was even one instance where a spooked carriage driver thought he saw the ghost before abandoning his passengers and fleeing on foot. There are other reports of women fainting to death at the sight of the purported ghost, though there was no evidence that the spirit actually existed.

Eventually, some residents of the community got their hysteria in check and determined the ghost was most likely someone in a sheet who was intentionally scaring people as a prank. Others, however, maintained that a spirit was causing havoc from beyond the grave. One such believer was Francis Smith, who one evening mistook bricklayer Thomas Millwood — who wore an all-white outfit for his profession — for the supposed ghost, and shot Millwood dead in the street. Smith went on trial and was convicted of murder, yet he still garnered sympathy from townsfolk who were hysterical with fear. Smith’s sentence was reduced to one year of imprisonment, leading to a series of debates about whether someone could be held liable for a crime based on mistaken beliefs, as Smith committed the crime only after being deluded into believing there was a ghost in the neighborhood. 

The Mad Gasser of Mattoon

Mattoon, Illinois, is a small town that was overcome by widespread panic in 1944, when reports of a “Mad Gasser” swept over the community. On September 1, a woman named Aline Kearney was overcome by a “sickening, sweet odor” that resulted in the temporary paralysis of her legs. Kearney’s husband arrived at the house shortly after and claimed to see a tall man wearing dark clothing and a tight-fitting cap standing outside the window, whom he chased until the mysterious man disappeared. Kearney’s condition returned to normal after 30 minutes, but this was just the first of many similar disturbances to come. After word spread of the Kearney incident, other townsfolk claimed they also suffered paralytic symptoms after smelling unusual odors. The panic grew to the point where chemical weapons experts were brought into the community. Armed gangs also began roaming the streets to try to find the “Mad Gasser” and bring them to justice.

There were many theories as to the identity of the mysterious menace, ranging from a chemistry teacher to an escaped Nazi prisoner of war. But in the end no assailant was ever found, and it’s highly unlikely that one ever even existed. Many of the anecdotal gassing incidents were fueled by mass hysteria, as one woman was simply overcome by odors from a spilled bottle of nail polish. It’s also theorized that years of wartime-related stress, combined with reports of chemical weapons being used overseas, added to the overall sense of communal anxiety in Mattoon.

Tanganyika Laughter Epidemic

Laughter is the best medicine, but it can also be a most perplexing symptom. In 1962, a laughter epidemic struck students at a girls’ boarding school in Tanganyika (now Tanzania). The mysterious giggles first appeared in January in a town called Kashasha, where three students began hysterically laughing from completely out of nowhere. Despite efforts to calm the girls, their perpetual howling was contagious, as dozens of other students also began experiencing laughing fits that lasted anywhere from a few hours to 16 days.

Doctors were unable to explain the phenomenon, and the root cause remains unclear even today. Some historians believe that the laughter was a visceral reaction to living in such a strict cultural environment, but that theory is far from certain. With no idea about how to quell unstoppable laughter, the school had no choice but to temporarily close in March, but that decision only led to more problems. As the girls returned home, they mysteriously “infected” each of their communities with the same insatiable urge to laugh uncontrollably. Laughter spread like wildfire throughout the country, leading to 14 separate school closures and affecting more than 1,000 people. It took roughly two years for the epidemic to completely dissipate, and thankfully, nobody suffered any long-term medical effects during that time.