In the disassortative structure (left) both competitors can coexist whereas the assortative structure (right) leads to a winner-takes-all scenario. (Image: Libby et al, 2017, Scientific Reports)

While single-celled organisms typically only make it into political discussion during insults, it turns out that modeling their behavior may give researchers a better handle on how political movements survive and spread.

In a new paper published in Nature Scientific Reports, researchers modeled systems where strategies or ideologies compete for members. By varying the extent to which members of a given system worked offensively or defensively, trying to convert individuals to their “side” or trying to keep similar individuals, they found some general principles that may begin to explain how differing strategies play out.

“The original angle for this was not a political slant. It was actually algae,” said study author Eric Libby, an SFI Omidyar Fellow who studies communities of unicellular microbes. But, he noted, "I think that the political handle on this is probably more intuitive."

Initially, Libby and SFI Research Fellow Laurent Hébert-Dufresne were looking at how algae evolve differing complex life cycles, such as which nutrients to absorb. After a working group with their collaborators, they saw it might help explain dynamics in a population where two groups compete for resources — in this case, voters.

In the original simulation model developed, which included just two distinct groups, individuals displaying one ideology might adopt the other if they were around enough people with the opposite beliefs seeking to influence them.

Over time, the researchers found that when two competing ideologies squared off with (predominantly) offensive strategies, many individuals would convert from one side to the other, and both parties would persist. Meanwhile, when both ideologies were more defensive, rather than lead to a stalemate, the less defensive group disappeared entirely, as a small initial loss would ultimately be amplified. A fifty-fifty offense-defense mix was found to be the best strategy.

But when a third party was added to the mix, the winning strategy was one that used a level of offense higher than one opponent but lower than the other. There was no single best strategy. “If you have multiple strategies competing, there doesn’t seem to be an optimal solution,” explained Libby. “It really depends on who else you’re competing against.”

Read the paper, "Strategic tradeoffs in competitor dynamics on adaptive networks," in Nature Scientific Reports (August 8, 2017)