Insight is being gleaned from a mathematical model for fish:
In experiments where a minority of fish was trained to swim toward a yellow target, and a majority toward a blue target, the minority swayed the whole group more than 80 percent of the time. Then the researchers added "uninformed" fish to the mix, and a curious thing happened. "Adding those individuals dramatically changes the outcome of group decision-making," [study author Iain Couzin] said. "They inhibit the minority and support the majority view, and this allows the majority to be heard and that view to dominate." … "We thought, ‘Wow, that’s kind of interesting,'" Couzin said, "because you don’t normally think that adding uninformed individuals to decision-making processes would have that sort of democratizing effect."
The Dish 