Wizarding superstition

Harry Potter originally felt suspicious of the Marauder's Map (pictured above) because of Arthur Weasley's comment, "Do not trust anything which can think for itself, if you cannot see where it keeps its brain," a common superstition among members of the wizarding community.

Wizarding supersitions are common beliefs held by members of the wizarding community in non-physical (i.e. metaphysical (supernatural)) causalities, i.e. that one event causes another without any physical process linking the two events. Many of these are based ancient folklore and generational retellings. Ronald Weasley mentions that his mother is "full of" these. The superstitions, and the origins from which they stem, might be accurate sometimes but are not always reliable.

List of superstitions

• Never trust anything that can think for itself, if you can’t see where it keeps its brain. — It seems accurate when speaking of Voldemort's Horcruxes, especially used in the case of Tom Riddle's diary.

  

  Tom Riddle's Diary: something that could think without one being able to see its brain.

• May-born witches marry Muggles.
• Jinx by twilight, undone at midnight.
• When his wand's oak and hers is holly, then to marry would be folly. - though, according to Mr. Ollivander, this superstition is baseless.
• Rowan gossips, chestnut drones, ash is stubborn, hazel moans. - it refers to the personality of the masters of certain wand woods. According to Mr. Ollivander, this superstition has a "small nugget of truth": those witches and wizards best suited to ash wands are lightly swayed from their beliefs or purposes.
• Fir is the ‘survivor's wand’ - based on observations by Gerbold Octavius Ollivander, who sold fir wands to three wizards who subsequently passed through mortal peril unscathed.
• Wand of elder never prosper. - This may have been influenced strongly by Beedle the Bard's famous story The Tale of the Three Brothers, along with the bloody history of the Deathstick.
• Releasing a Portkey before it has arrived will result in death or serious injury.
• Bad luck can be prevented by turning three times on the spot and deliberately Splinching one's thumbs.
• Muggle-born witches/wizards are more likely to produce Squib children than those who have one or more wizarding parents.
• Muggle-born witches/wizards are generally less prone to certain magical illnesses than those who have one or more wizarding parent.
• Muggle-born witches/wizards are generally slower to show signs of magic in childhood than those who have one or more wizarding parent.
• Muggle-born witches/wizards have great natural rhythm.

Notable rumours and other common misconceptions

• According to Dumbledore's commentary in the The Tales of Beedle the Bard, it was originally believed in the seventeenth century that a blood traitor only sympathised with Muggles because they were insecure of their own magical ability. It was propagated through Brutus Malfoy's pure-blood propaganda. Over time, the counter-evidence to this was too high that this misconception was accepted for what it is; however, many still hold a negative view of Muggle-lovers despite no longer being seen as inferior.
• Many wizards believe that there is such a thing as werewolf cubs. Rubeus Hagrid was believed to be raising supposed werewolf cubs under his bed at some point during his time at Hogwarts School of Witchcraft and Wizardry. The 16-year-old memory of Tom Riddle retells this gossip to Harry Potter.
• In the 1991-1992 school year, the Hogwarts student body speculated that Rubeus Hagrid's evil brother Dirgah was the thing that was being kept inside the Forbidden Corridor.
• In 1995, it was believed that Albus Dumbledore was raising an army and that Harry Potter was troubled. This was fuelled by Cornelius Fudge's misguided regime and became obviously false after Fudge had been sacked.
• In 1997, some wizards were under the impression that Lord Voldemort could kill simply by looking at someone. It was a common enough misconception that Fred Weasley corrected them by announcing on PotterWatch that only a basilisk could do that.

Appearances

• Harry Potter and the Philosopher's Stone (video game) (Possible appearance)
• Harry Potter and the Chamber of Secrets (Possible appearance)
• Harry Potter and the Prisoner of Azkaban
• The Tales of Beedle the Bard
• J. K. Rowling Official Site