Josh WardleA software engineer who works for Reddit. was at home during lockdown when he had an idea.

His partner, Palak, was bored. She had finished all the word games in the newspaper. So, Josh made Palak her own puzzle. 

He named his new game Wordle. Every day, players get six chances to correctly guess a new five-letter word. Palak loved it. So did his family. 

Then, last autumn, he decided to share Wordle with the world. The game took off. In November, Wordle had just 90 players. Now, two million people play every day. 

But why is Wordle so popular? 

This is not the first puzzle craze. The Ancient Greeks and Romans loved to solve riddles. In 2005, sudokus were so popular that global pencil sales increased by 700%. 

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

Psychologists say that players enjoy the satisfying moment when they solve an anagram or fit a new piece into a jigsaw. The brain releases dopamine, a chemical that helps us feel pleasure. 

"Every time something is rewarding, we tend to want to do it more," says Carola Salvi of the University of Texas. Some people find puzzles addictive. 

Puzzles can also be a way of escaping reality during the pandemic, says academic Marcel Danesi. Unlike problems in the real world, puzzles have clear solutions. For some people, Wordle provides order in a chaotic world. 

Some say Wordle's success is mainly due to timing. During the pandemic, many people are communicating online. Wardle has created a simple way for players to share their result on social media and discuss it with friends or family.

"It makes us feel part of something," says one therapist. 

It is key for people working or learning at home to keep their brains busy. For many, puzzles are the answer. 

Yes: The evidence is clear. Solving puzzles releases feel-good chemicals in our brain and makes us happy. In 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.