A meme is an idea that is readily transmitted from person to person. But we humans are not perfect transmitters. While sometimes we repeat the idea exactly, often we change the meme, either unintentionally, or to embellish or improve it.
Take for example, the meme:
“No one should die because they cannot afford health care, and no one should go broke because they get sick. If you agree, post this as your status for the rest of the day”.
In September of 2009, over 470,000 Facebook users posted this exact statement as their status update. At some point someone created a variant by prepending “thinks that” (which would follow the individual’s name, e.g., “Sam thinks that no one…”), which was copied 60,000 times. The third most popular variant inserted “We are only as strong as the weakest among us” in the middle. “The rest of the day” at one point (probably in the late evening hours) became “the next 24 hours”. Others abbreviated it to “24 hrs”, or extended it to “the rest of the week”.
In all, using anonymized data, we detected 121,605 different variants of this particular meme which appeared in 1.14 million status updates. One can connect these variants together, in a manner similar to constructing a phylogenetic tree to trace the lineage of a particular genetic sequence.
Even more interestingly, fitness of variants is not uniform across all parts of the social network, but can sometimes depend on the niche.
[S]everal different parodies emerged, and by averaging the political leanings of those sharing a particular variant, we found the following: the original variant in support of Affordable Care Act (aka Obamacare) was propagated primarily by liberals, while those mentioning government and taxes slanted conservative.
Sci-fi variants were slightly liberal, alcohol-related ones slightly conservative, while opposition to cancer was uniform. Just as certain genetic mutations can be advantageous in specific environments, meme mutations can be propagated differentially if the variant matches the subpopulation’s beliefs or culture.