Jinn is a catch-all Arabic term for a variety of beings that, in Muslim doctrine, are neither humans nor angels but something in between. Whereas Adam, the first man, is said to have been created from earth and angels are beings of pure light, jinn were created from “smokeless fire.”
There are a couple of terminological traps that need to be addressed before we go any further. In Arabic, the singular masculine form is jinni. The singular feminine is jinniyah. Jinn is the plural form. Sometimes the words are spelled with a “d” in it (for example, djinn). Jinni is sometimes rendered in English as “genie,” but this isn’t technically correct. The “genie” spelling creates the false impression that the word is related to Latin genius, meaning “spirit.” In fact, jinni (and related forms) comes from an Arabic word meaning “hidden.” These beings are thus more or less “the hidden folk.”
Also, the jinn of the Arabic world have a close counterpart in the peris of Persia (modern Iran). It is a matter of speculation which came first, but the two mythologies clearly cross-pollinated each other throughout the Middle Ages. Both groups are said to live primarily in Koh-e-Qaf, the Mountains of Qaf (i.e., the Caucasus Mountains).
The image of jinn as magical slaves trapped inside lamps or bottles is largely derived from the Thousand and One Nights. What is often overlooked is that these stories depict individual jinn who have been reduced to slavery by powerful magicians. Jinn are naturally free beings that may be either helpful or malicious toward human beings.
Jinn are not immortal, though their lifespans far exceed that of humans. Like humans, they marry, have children. Sometimes they even marry humans and produce hybrid children with characteristics of both parents. (A Syrian legal treatise from the fourteenth century condemns such marriages.) They eat and drink as mortals do. They can also be killed either by other jinn or by mortals.
Even so, jinn are decidedly magical beings. They have the ability to travel quickly from place to place, and they are especially known as accomplished shapeshifters, often appearing in the forms of snakes, vultures, dogs, cats, or other animals. They can also take on human form, although evil jinn often appear hideously deformed.
In stories, jinn inject a note of unpredictability. They might reward the protagonist or unfairly punish him or her.
There are more than a few points of connection between the faery lore of Europe and the jinn lore of the Middle East. Both types of beings possess great magical powers, including invisibility and shapeshifting. Both are sometimes said to intermarry with humans—although jinn, like the elves of Scandinavia, seem to have a better track record in this regard than the Fair Folk of the Celtic nations.
Finally, like the faeries of Celtic folklore, jinn are vulnerable to iron. If anything, they are even more frightened of the substance, and in some legends can be put to flight by even the threat of iron.
There are many varieties of jinn within Middle Eastern folklore. In addition, under Muslim influence, many cultures outside the Middle East have adjusted their own indigenous beliefs about supernatural beings to conform to jinn-lore, often explicitly equating these previously existing entities with jinn. Some of these “hybridized” jinn types are: the asaid or zar of Ethiopia, the bori of northern Nigeria, the gnena or guinné of West Africa, and the bidadari or bediadari of Malaysia.