Josh WardleA software engineer who works for Reddit. was sitting in his New York apartment when he had the idea.

His partner, Palak, was bored. The city was in lockdown. She had finished the crossword and the spelling bee. So Josh decided to make Palak her own puzzle.

The result was Wordle, a daily word game in which players get six chances to guess a five-letter word. Palak loved it. So did Wardle's family, who quickly became obsessed with the game.

Then, last autumn, he decided to share his creation with the world. The response was greater than anything he could have imagined. In November, Wordle had just 90 players. Now, two million people play every day.

Wordle is not the first puzzle craze to take over the world. The Ancient Greeks and Romans loved to figure out riddles. In 1817, Chinese tangramsThe tangram puzzle consists of seven flat pieces which together make a square.  captivated people across Europe. Nearly two centuries later, in 2005, global pencil sales increased by 700% when newspapers introduced a new audience to sudokuA type of puzzle in which you have to work out missing numbers. Although the name is Japanese, it is believed to have been invented by an American in the 1970s..

"These activities can be challenging, brain-aching and time-consuming, but we relish them anyway," summarises one journalist.

Psychologists point out that what these puzzles share is a moment of insight - the aha! moment when you solve the anagram or fit a new piece into the jigsaw.

"When you 'win' or complete a puzzle, your brain releases a rush of positive emotions," says psychotherapist Sally Baker. For many gamers, the release of dopamineA hormone and neurotransmitter that plays several important roles in the brain and body, providing us with positive sensations, rewarding us for evolutionarily good behaviours like eating food. can be addictive.

Experts once thought that puzzles could even prevent mental decline in old age. Now, new research suggests this is just a myth, but psychologists still think the joy caused by puzzles could be an evolutionary advantage.

"Every time something is rewarding, we tend to want to do it more," says Carola Salvi of the University of Texas. Insight stimulates curiosity, which in turn promotes the advance of science, technology and the arts.

And during the pandemic, puzzles can be a form of escapism, says anthropologistSomeone who studies human beings and societies. The word "anthropology" comes from the Greek "anthropos", meaning "human". It developed as a subject in Europe in the 19th century, although some regard the Arab historian Ibn Khaldun as the first anthropologist. Marcel Danesi. Real-world problems do not have clear solutions like Wordle or sudokus. For Danesi, "puzzles give psychological order to the chaos we feel".

But others think Wordle's success may not be about just the puzzle itself. Users can only play once a day, increasing their anticipation for the next round. And unlike many online games, it is free. "It's what the web was like when we first had it, it was much more playful," says one game designer.

During the pandemic, many have been drawn to the online community. Wardle has created a simple way for players to share their results on social media and discuss the game with family and friends. "It makes us feel part of something and gives us a sense of connectivity many of us are craving," Baker explains.

One thing is clear: with so many people working and learning from home, keeping our brains stimulated is more important than ever. For many, puzzles are the solution.

Yes: The evidence is clear. Solving puzzles releases feel-good chemicals in our brain and makes us happy. In a lockdown, they are the perfect distraction from the chaos of the real world. 

No: Puzzles bring temporary satisfaction, but they are not the key to happiness. Humans need love, goals, art and more to be truly happy. And, as Wordle users have found, failure can be frustrating. 

Or...? Wordle's success is more about the game's ability to help players connect with an online community than the puzzle itself. It is sharing their life with others that brings Wordle users joy.