What are superstitions and why do we believe in them?

Have you ever rejoiced at finding a four-leaf clover, saluted a magpie or knocked on wood? What about worrying you'll experience bad luck after breaking a mirror, walking under a ladder or opening an umbrella indoors?

These are all examples of superstitions - beliefs tied to magic, luck or fear of the unknown rather than science or reason. It could be as simple as wearing your lucky socks every time you watch your favourite football team play, or crossing your fingers before opening exam results.

Their origins are often shrouded in mystery, but BBC Bitesize has taken a look at some of the most well-known legends…

When wishing someone good luck, we often say that we’ll keep our fingers crossed for them – the middle and index fingers, specifically. But why?

There are a couple of theories about the origins of this gesture. One idea is that it was an ancient pagan custom, which actually required two people. They would cross fingers with each other, and any wishes they made at the point when their fingers met would be kept safe until they could come true.

Another theory is that crossing fingers was a way for early Christians to call upon the power of Christ’s crucifixion at a time of persecution, especially if they had to lie when facing torture. To this day, some people still cross their fingers behind their back if they’re telling a lie or making a promise they can’t keep.

However, British folklorist Steve Roud previously made the point that there is no written evidence for either of these origin stories. In fact, no one has found any mention of crossing fingers before 1890.

When it is mentioned, Steve says, it's in the context of providing protection from witches rather than general good luck. There is evidence dating back to Shakespeare's time of people warding off witches by hiding their thumb inside their hand and making a fist shape.

Steve believes that this idea of protection also explains why we cross our fingers when lying: "If I do that and tell a lie, I'm protecting against fate punishing me for telling a lie. It's the protection notion, rather than the good luck notion."

Walking under a ladder, stepping on a crack in the pavement, a black cat crossing your path – lots of seemingly innocent things are considered to bring bad luck.

Another is breaking a mirror, which is said to bring seven years’ misfortune. This superstition is said to have its roots in ancient civilisations like the Romans and Greeks. Reflections were believed to hold a person’s soul or spirit, so breaking one would fracture it. The Romans believed it took seven years for a soul to replenish itself.

A related theory goes that these ancient people believed mirrors were portals used by gods to observe humans, so breaking them was an insult punished by bad luck – a similar idea is explored in Alice in Wonderland. Mirrors at this time were usually made of bronze, copper or silver alloys rather than glass.

A more practical explanation is that, once glass mirrors became more common during the Renaissance, they were such a luxury item that a servant who broke one belonging to their master would owe seven years’ worth of labour to pay for it.

The bad luck could also be more physical than spiritual. Early mirror-makers sometimes used mercury, a toxic chemical, so shattering one could release this poison into the air and damage health.

Of course, there’s a very immediate reason to fear breaking a mirror, too – the risk of injury from cutting yourself on shards of broken glass.

Hanging up a horseshoe to ward off evil is closely associated with St Dunstan, the patron saint of goldsmiths, locksmiths and jewellers.

The story goes that, while living as a hermit in Glastonbury, he was visited by Satan. The devil asked Dunstan to use his blacksmithing skills to shoe his hoof.

Dunstan did so, but he attached the shoe in a way that would cause severe pain, then refused to remove it until the devil had promised he would never enter anywhere a horseshoe was hung.

Horseshoes were usually nailed into doors, or set into the steps leading up to a house. They were also often nailed to the masts of ships - this was the case on HMS Victory, Lord Nelson's ship, during the Battle of Trafalgar in 1805.

Traditionally, horseshoes were made of iron, which was itself thought to have mystical properties. If you happened to find a piece of iron, Steve says it was thought to offer protection against witches. This goes back to the 14th century, but it was crucial you found it by chance: "You can't engineer your fate."

Steve added that hanging up horseshoes for luck is mentioned as early as the 16th century, but that it isn't necessarily linked to the story of St Dunstan. In Italy, you might still hear people saying that they touch iron if they think they’ve jinxed themselves.

Umbrellas haven’t always looked exactly the way they do now – and that may explain why many of us still believe it’s bad luck to open one indoors.

The modern umbrella was invented by Samuel Fox in the 19th century. This earlier version was unwieldy, operated by squeezing stiff triggers that opened hard metal spokes. There was no in-between – umbrellas were either completely closed or springing into life, potentially hitting a person or an expensive ornament.

However, the Victorians weren’t the first to design umbrellas. They date as far back as Ancient Egypt, where shades made from papyrus and peacock feathers were used as protection from the sun rather than the rain. Some believe our modern superstition ties back to a fear of disrespecting the sun gods by using one inside, in turn causing them to bring misfortune upon the home.

Whichever you believe, it might be best to leave umbrella-opening as an outdoor activity – just to be on the safe side…

If there’s no iron around and you fear you have somehow jinxed yourself, you might touch some wood instead. It's said to help us avoid tempting fate.

There are numerous different explanations as to why this practice is thought to guard against bad luck. One theory links to a pagan belief that spirits and gods lived in trees. By knocking on a tree trunk, you could communicate with them and ask for their protection, or thank them for good luck.

Alternatively, if the spirits were of an evil nature, knocking could have scared them away and stopped them from reversing any good luck they witnessed.

As with the crossing of fingers, a Christian interpretation says that touching wood calls upon the power and protection of the crucifixion and the wood of the cross. However, Steve argues it's actually a far more modern custom, with its roots in a playground game from the 19th century called Tiggy Tiggy Touch Wood.

A variation on the traditional game of tag, players could avoid being caught by touching a piece of wood. The wood gave them protection, which is how the superstition might have arisen.

Steve says the earliest reference we have for touching wood is 1810, and that 19th century references link it to this children's game. It's only in the 20th century that we see claims of it being an ancient tradition, whether linked to paganism or Christianity.

You might have heard the old nursery rhyme about magpies before – one for sorrow, two for joy…

But why is seeing one magpie considered bad luck, and why do we salute them? The superstition is believed to be based on the fact that magpies mate for life, so seeing one on its own might suggest the other has died.

The thinking is that we should salute it to ward off this bad luck. That explains why you may have heard someone say, ‘Good morning, Mr. Magpie, how is your wife at home?’

The nursery rhyme dates back to the 18th century, but it’s based on a much older practice called ornithomancy – reading omens from bird behaviour. Various cultures have beliefs about the evil nature of magpies.

The Christian tradition goes that they were the only bird not to mourn at the crucifixion, while Scottish folklore says magpies have a drop of the devil’s blood under their tongues. By the 19th century, they were so feared that they were nearly hunted to extinction.

However, in ancient Rome, magpies were viewed as symbols of good fortune because of their intelligence and were sacred to Bacchus, the Roman god of wine. But by the Middle Ages, this inquisitiveness had earned them an association with theft - especially where shiny objects were concerned.

Perhaps an unfair reputation, but still an interesting history.

This article was written in June 2021 and updated in October 2026

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