Origin of superstitions

Já se perguntou por que batemos na madeira ou tememos sexta-feira 13? Esta apresentação revela as origens surpreendentes das superstições globais – desde moedas da sorte até gatos ‘amaldiçoados’. Você descobrirá como mitos antigos, crenças religiosas e até truques engenhosos moldaram tradições que seguimos até hoje. 
(Ever wondered why we knock on wood or fear Friday the 13th? This presentation unveils the surprising origins of global superstitions — from lucky pennies to cursed cats. You’ll discover how ancient myths, religious beliefs, and clever tricks shaped traditions we still follow today.)

Say “bless you” after a sneeze
The tradition of saying “bless you” after a sneeze dates back to ancient times, when people believed a sneeze could expel the soul from the body. Both sneezing and yawning were seen as dangerous moments in Greek and Roman culture –– times when the soul might escape and not return. Blessings were offered as a way to shield their wandering souls.

Dizer “saúde” a quem espirra
A tradição de dizer “saúde” após um espirro remonta à antiguidade, quando se acreditava que um espirro poderia expelir a alma do corpo. Tanto espirros quanto bocejos eram vistos como momentos perigosos na cultura grega e romana – ocasiões em que a alma poderia escapar e não retornar. As bênçãos eram oferecidas como proteção para essas almas errantes.

Mango + milk = poison
Until nowadays, some brazilians believe that taking milk and mango together could lead to death. The myth originated in the times of slavery from the 16th to the 19th century. At that time it was customary to nourish serfs mainly with mangos because the fruits were abundant and therefore cheap. Milk, on the other hand, was extremely expensive. To deter slaves from consuming dairy, owners spread the myth that the combination was poisonous.

Manga + leite = veneno?
Até hoje, alguns brasileiros acreditam que consumir manga com leite pode ser mortal. O mito surgiu durante o período escravocrata (séculos XVI-XIX), quando os senhores alimentavam os escravos com mangas (baratas e abundantes) e espalharam que a combinação com leite (caro e reservado aos donos) era venenosa – uma mentira para evitar que escravos consumissem laticínios.

Unlucky number 13
The fear of the number 13 traces back to two infamous dinner parties across different mythologies. In Christianity, Judas Iscariot –– the betrayer of Jesus –– was the 13th guest at the Last Supper. Meanwhile, in Norse mythology, Loki, the trickster god, crashed a divine gathering as the 13th guest, leading to chaos and the accidental shooting of the god of joy. These twin tales of betrayal and mischief cemented 13’s reputation as an unlucky number –– making no one want to be the 13th guest at any table.

O número 13 e o azar
O medo do número 13 vem de dois jantares infames: na Última Ceia, Judas (o traidor) foi o 13º convidado; na mitologia nórdica, Loki (deus trapaceiro) causou caos como 13º convidado em um banquete divino. Essas histórias cimentaram a fama do 13 como número do azar.

Black cats bring bad luck
In 1233, Pope Gregory IX declared black cats incarnations of Satan. Devout Christians burned them alive during festivals. By the 1300s, their near-eradication in parts of Europe had unintended consequences: with fewer cats to hunt rodents, disease spread more easily. The superstitions evolved linking black cats with witchcraft –– some believed they were witches in disguise, others that they’d become witches after seven years. During the Salem witch trials, even owning one could be a death sentence.

Gatos pretos dão azar
Em 1233, o Papa Gregório IX declarou que gatos pretos eram encarnações de Satanás. Cristãos devotos os queimavam vivos em festivais. No século XIV, seu quase extermínio na Europa teve um efeito colateral: menos gatos = mais ratos = mais doenças. Na era das caças às bruxas, ter um gato preto podia levar à execução.

Entering room with left foot
Many cultures believe entering a room with your left foot first invites bad luck, while the right foot welcomes positivity. This superstition is especially sacred in Asian wedding traditions –– brides always cross the threshold right-footed to ensure a fortunate marriage.
Rooted in ancient beliefs about left-side negativity (often linked to the “unlucky” side of the body), this practice endures in families worldwide.

Entrar com o pé esquerdo
Em muitas culturas, entrar em um lugar com o pé esquerdo atrai má sorte, enquanto o pé direito atrai positividade. Em casamentos asiáticos, a noiva sempre cruza a soleira com o pé direito para garantir um casamento abençoado – uma crença ligada ao simbolismo negativo do lado esquerdo do corpo.

Lucky horseshoe
The lucky horseshoe’s magic comes from three ancient beliefs:
• Pagan Symbolism: its crescent shape honored Diana, moon goddess of fertility
• Iron’s Power: Europeans believed metal repelled evil spirits (7 nail holes = extra luck)
• Saint Dunstan’s Trick: as a blacksmith, he nailed a shoe to the Devil’s hoof. In agony, the Devil agreed never to enter a house with a horseshoe nailed above the door if Dunstan would simply agree to remove the shoe.

A ferradura da sorte
A ferradura traz sorte por três razões:
• Paganismo: seu formato de lua homenageava Diana, deusa da fertilidade
• Poder do ferro: europeus acreditavam que o metal repelia espíritos malignos
• Lenda de São Dunstan: o ferreiro pregou uma ferradura no casco do Diabo, que prometeu nunca entrar em casas com ferraduras na porta.

Four-leaf clover
With odds of 1 in 10,000, four-leaf clovers are nature’s rare lucky charms. Legend says Eve plucked one as she left Eden, preserving a memory of paradise. Today, each leaf carries meaning faith, hope, love and luck.
This sacred connection transformed them into universal symbols of fortune, making every discovery feel like finding a piece of celestial magic.

Trevo de quatro folhas
Com chances de 1 em 10.000, trevos de quatro folhas são amuletos raros. A lenda diz que Eva colheu um ao sair do Éden. Cada folha simboliza fé, esperança, amor e sorte – uma conexão sagrada que os tornou símbolos universais de boa fortuna.

Knocking on wood for good luck
The superstitious habit of knocking on wood has roots in ancient pagan beliefs that powerful spirits lived within trees. People would rap their knuckles against tree trunks to either wake the protective spirits and request good fortune, or cancel out any bad luck they might have accidentally summoned by speaking it aloud. This action served as both a spiritual alarm clock and an “undo button” against misfortune.

Bater na madeira
Bater na madeira vem do paganismo, que acreditava em espíritos protetores nas árvores. Batia-se no tronco para:
• Acordar os espíritos e pedir sorte
• “Cancelar” má sorte mencionada em voz alta
Era um “despertador espiritual” e um “botão de desfazer” contra o azar.

The lucky penny
Ancient civilizations revered copper as a divine gift, believing coins carried protective magic. But with their dual-sided nature came a cosmic split:
• Heads-up: blessed by the gods (good luck)
• Tails: vulnerable to evil forces (bad luck)
This tiny metal disc became a physical manifestation of humanity’s eternal struggle between fortune and misfortune.

Moeda da sorte
Civilizações antigas viam o cobre como presente divino. Moedas tinham lados opostos:
• Cara: abençoada pelos deuses (boa sorte)
• Coroa: vulnerável a forças malignas (má sorte)
Um pequeno disco que simboliza a eterna luta entre sorte e azar.

The unholy triangle
The fear of walking under ladders traces back to sacred geometry. In Christianity, the triangle symbolizes the Holy Trinity (Father, Son, Holy Spirit). A leaning ladder recreates this shape against a wall, turning the space beneath it into a blasphemous zone.
Passing through “breaks” the divine triangle, inviting misfortune –– a belief that merged with broader superstitions about disrupting spiritual harmony.

Passar debaixo de escada
Na geometria sagrada cristã, a escada apoiada na parede forma um triângulo (a Santíssima Trindade). Passar por baixo “quebra” esse símbolo divino, atraindo infortúnio – uma crença que se misturou a superstições sobre perturbar a harmonia espiritual.

Trimming nails at night
In India and Japan, cutting nails after sunset is considered an invitation for bad luck –– a belief deeply rooted in Hinduism and Islam. This superstition warns that nighttime activities attract negative energy.
But there’s wisdom behind the warning: before electricity, poor visibility made nail-trimming hazardous after dark.

Cortar unhas à noite
Na Índia e no Japão, cortar unhas após o pôr do sol atrai má sorte (segundo hinduísmo e islamismo). Mas há lógica: antes da eletricidade, a escuridão tornava o hábito perigoso – mostrando como superstições muitas vezes têm origens práticas.

Broken mirror & bad luck
The ancient Romans believed mirrors held fragments of our souls –– so breaking one meant shattering a person’s health and well-being.
Fortunately, they also thought souls renewed every seven years. That’s how long the unlucky mirror-breaker would endure misfortune before emerging whole again.

Quebrar espelho = 7 anos de azar
Os romanos acreditavam que espelhos guardavam fragmentos da alma. Quebrar um significava quebrar a saúde e o bem-estar. Mas havia esperança: a alma se renovava a cada 7 anos – tempo de azar para o desastrado.

Wishing on a star
The ancient Greek astronomer Ptolemy believed shooting stars were a celestial sign –- proof that the gods had opened the heavens to gaze upon Earth. According to his theory, these fleeting streaks of light slipped through the divine barrier whenever the gods looked down, making them the perfect moment to send up a wish. For centuries, this idea inspired the tradition of wishing on shooting stars.

Fazer pedido a uma estrela cadente
O astrônomo Ptolomeu via estrelas cadentes como sinais de que os deuses observavam a Terra. Segundo ele, esses raios de luz fugazes atravessavam o “véu divino” quando os deuses olhavam para baixo – criando o momento perfeito para pedidos.

Opening an umbrella indoors
In ancient Egypt, umbrellas were more than sun protection –– they were sacred symbols of royalty. Crafted from papyrus and peacock feathers, their designs honored Nut, the sky goddess. Their shade was so divine that only nobility could stand beneath them; commoners risked committing sacrilege by entering their shadow. Historians suggest that opening one indoors doubly offended the gods: it violated the umbrella’s purpose and insulted the sun god Ra by rejecting his light.

Abrir guarda-chuva dentro de casa
No Egito Antigo, guarda-chuvas eram símbolos reais (feitos de papiro e penas de pavão). Sua sombra era tão sagrada que só nobres podiam usá-los. Abrir um dentro de casa ofendia o deus-sol Rá – rejeitando sua luz.

Fingers crossed
Crossing fingers for luck traces back to pre-Christian Europe, where intertwining two people’s index fingers was believed to:
• Trap good spirits in the X-shaped symbol
• Seal sacred promises between oath-takers
Over centuries, it simplified to solo finger-crossing—first both index fingers, then just one hand’s index and middle fingers. Today, we still use this ancient “spiritual shortcut” to hope for the best.

Cruzar os dedos
Cruzar dedos para sorte surgiu na Europa pré-cristã, onde entrelaçar indicadores com outra pessoa:
• Capturava espíritos bons no símbolo em “X”
• Selava promessas sagradas
Com o tempo, simplificou-se para cruzar os próprios dedos – um “atalho espiritual” que usamos até hoje.