Why Do So Many Cultures Have Flood Myths? The Most Widespread Story on Earth

The Mesopotamian flood is the earliest recorded and appears in several texts. The Sumerian tale of Ziusudra is the oldest fragment; the Akkadian Atrahasis epic, from around 1700 BC, gives the fullest account, in which the gods send the flood because humanity has become too numerous and noisy for them to sleep; and the version everyone knows is embedded in the Epic of Gilgamesh, where the survivor Utnapishtim tells the hero his story. The parallels with Genesis are specific rather than general: divine warning to one man, precise instructions for a boat sealed with pitch, the loading of family and animals, a storm of fixed duration, grounding on a mountain, the release of birds in sequence to test for dry land, a sacrifice on landing at which the deity smells the offering, and a promise not to do it again. The Babylonian text was deciphered by George Smith in 1872, who is reported to have started undressing in excitement in the British Museum reading room, and its publication caused a theological crisis in Victorian Britain.

The distribution is close to global, and the details vary in instructive ways:

• •Greek: Deucalion and Pyrrha survive a flood sent by Zeus in a chest, and repopulate the world by throwing stones over their shoulders, which become people
• •Hindu: Manu is warned by a fish, which he had saved when small and which grows enormous, and which tows his boat to safety on a northern mountain
• •Chinese: the emphasis falls not on survival but on engineering, with Yu the Great ending a flood by dredging channels to the sea over thirteen years, which founds the first dynasty and makes the story about governance rather than divine anger
• •Aztec and Maya: humanity is destroyed and remade repeatedly through successive world ages, one ended by water
• •Australian Aboriginal traditions: several describe a great flood, in some cases connected to a frog that swallows all the water
• •Norse: the blood of the slain giant Ymir drowns the race of frost giants, with two surviving in a hollowed tree
• •Many Pacific, North American and African traditions carry versions, though sub-Saharan Africa has notably fewer than other regions, which argues against the story being universal in the strict sense

Scholars offer three accounts and they are not exclusive. Diffusion holds that the story spread from one source, which explains the tight Mesopotamian and biblical correspondence well, since the two cultures were in direct contact and the Judaean elite spent decades in Babylon, and explains the Greek and Indian versions plausibly; it works less well for the Americas and Australia. Independent invention holds that floods are the most common natural disaster in the world, that most early civilisations grew on rivers and coasts, and that any society that has experienced a catastrophic inundation will generate a story about it, particularly one carrying the moral that survival depends on heeding a warning. Memory of real events is the third, and the candidates include the end of the last ice age, when melting ice raised global sea level by roughly 120 metres over several thousand years and drowned enormous areas of inhabited coastal land, including Doggerland between Britain and the continent, and the Black Sea, where a disputed hypothesis proposes a rapid inflow from the Mediterranean around 7,600 years ago.

The variations matter more than the similarities, because they show what each culture used the story for. The Mesopotamian gods send the flood out of irritation at human noise and overpopulation, and they regret it partly because they miss the sacrifices, which presents the divine as capricious and dependent. Genesis makes the cause moral, human wickedness, and the outcome a covenant, which turns the same events into an argument about justice and promise. The Chinese version removes the divine motive entirely and makes the hero an administrator whose virtue is persistence and whose method is public works, which is a statement about what makes a legitimate ruler. The Greek version is brief and interested chiefly in how the human race was restarted. A single story used in four ways tells you about the four societies, which is why comparative mythology finds the divergences more informative than the shared plot.

Attempts to find a single global deluge have failed completely, and the geological record rules one out: there is no worldwide flood layer, the water does not exist on the planet to cover the mountains, and the sedimentary sequences of different continents record entirely different histories. Nineteenth-century excavators at Ur and Kish found thick river silt layers and announced they had found the flood, but the layers date to different centuries at different sites, which makes them local Mesopotamian inundations, of which there were many, rather than one event. The Black Sea hypothesis, proposed by William Ryan and Walter Pitman in 1997, remains contested, with later sediment work suggesting a slower and less dramatic rise than the original catastrophic model. The honest position is that many real floods happened, that the end of the ice age drowned a great deal of occupied land within cultural memory, and that no one of these needs to be the flood for the stories to be explained.

The flood story is the most widely distributed narrative in world mythology, with the oldest written version in Mesopotamia more than a thousand years before Genesis and matching it in specific details including the pitch-sealed boat, the birds released to test for land and the sacrifice on landing. The distribution is explained by a mixture of diffusion between neighbouring cultures, independent invention where floods are the commonest disaster, and memory of real events such as the post-glacial sea level rise. No single global flood is compatible with the geological record.