Last month, amid the hubbub surrounding alleged voter-roll irregularities across the U.S., registration paperwork was mailed to a deceased goldfish in the Chicago suburbs by the name of Princess Nudelman. The story made headlines and even became fodder for a Saturday Night Live punch line. But new research suggests that Princess may have been an informed voter, after all, had she been around to see Election Day: new research indicates that schools of fish choose their leaders by consensus, weighing the preferences of peers before making a choice.
The study, published online today by the journal Current Biology, details the way that the three-spined stickleback, a bony freshwater fish, uses social cues to select the more appealing of two candidates. As the voting pool grew in size, the proportion of fish making the "correct" choice—that is, following the fitter candidate, as indicated by visual cues such as size, color and spottiness—increased, indicating a beneficial feedback mechanism at work. (In truth, the process was more akin to caucusing than voting, as the sticklebacks' preferences were visible to their peers.)
The data gathered by the researchers, led by math professor David Sumpter of Uppsala University in Sweden, conform closely to the so-called quorum-response rule. In this model, a few individuals are able to discern a difference between the two candidates and so take the lead in making a choice. The rest of the group hangs back, "waiting until a threshold number of fish have made a particular decision," Sumpter and his colleagues write. "The threshold increases with group size, and thus so, too, does the accuracy of the decision."
[UPDATE: Click here to hear a 60-Second Science podcast on the research.]
CREDIT: Christopher Hudson/iStockphoto