The formation and biodiversity of atoll islands in the Pacific

During the hongi, a traditional Maori greeting where noses are pressed together, pulling away early is disrespectful, as it breaks the sharing of breath and connection.

In Russian culture, even numbers of flowers are associated with funerals and death, making it rude to give them for positive occasions like birthdays.

At ancient Egyptian banquets, guests wore cone-shaped wigs made of scented wax that melted to release fragrance, a sign of status and politeness.

Turning your head away or drinking facing an elder is considered disrespectful in Korean culture; you should face away to show respect.

Using the left hand to eat is considered impolite in many Middle Eastern cultures, as it is traditionally reserved for hygiene purposes.

Women used fans to communicate specific messages (e.g., fanning slowly meant 'I’m married'), and improper use could lead to social misunderstandings.

In Thai culture, the head is considered the most sacred part of the body, and touching it, especially a stranger’s, is disrespectful and invasive.

Belching loudly was considered a polite way to signal satisfaction with a meal in medieval Europe, showing appreciation for the host’s food.

Sticking chopsticks upright in a bowl of rice resembles incense sticks at funerals, making it a disrespectful act associated with death.

In ancient Rome, the left hand was considered unclean, and using it to eat was seen as impolite, as it was associated with hygiene practices.