Someone gets bullied in every society. It's bad luck on the victims, but in primitive social groups they might do best to put up with it. If the advantages of group living outweigh the costs of being bullied, evolution might leave some animals resigned to their victim status, thus stabilising the group...
Lehmann thinks that animals form groups because sticking together reduces the risk from predators. "As long as the predation pressure keeps up, the group stays together," she says.
As a result, low-ranking marmots might evolve to cope with being victimised, because it's better than being eaten. "Staying alive is the most important thing," Lehmann says.
Now that there's not much of a chance of being killed by predators, the low-ranking marmots (liberals) lash out.