Why Different Myths Tell Similar Stories

The first plot is easier to explain than the others. People settled near rivers and seas, floods happened everywhere, and memories of a major catastrophe could easily turn into a story about the end of the world. The same events can produce the same stories without any borrowing.

Both versions can be tested, though not easily. Borrowing is suggested by matches in small details that do not follow from the plot: a name, a number, or a strange detail. Independent invention, by contrast, produces a matching overall pattern while the details are completely different.

There is also a third explanation, the dullest and perhaps the strongest. Stories survive as long as people retell them, and people retell the ones that are easy to tell: they have a clear sequence, one main character, and an understandable goal. All the other versions simply did not survive long enough to be recorded.

The popular idea that all the world's myths follow a single hero's journey needs a qualification. The pattern is so broad that almost any story can be made to fit it, while anything that does not fit is declared a variation. A claim that cannot be disproved is weak as an explanation.

It is also useful to remember how these similarities are found. Researchers look for similarities and almost always find them, because the number of plots is finite while there are thousands of myths. Some similarities are inevitable simply by arithmetic, without any shared cause.