"I like pigs," Winston Churchill supposedly once said. "Dogs look up at us, cats look down on us, but pigs treat us as equals. "Whether Churchill's contemporary George Orwell also liked pigs is less clear. But he, too, surely saw something in them that was lacking in other domestic beasts, for it was they who ended up running the show in novel Animal Farm. Pigs, then, are intelligent social creatures.
And, like all animals, they sometimes fight. A study just published in Animal Cognition by Ivan Norscia, a biological anthropologist at the University of Turin, in Italy, and his colleagues, looked at how a group of 104 domestic pigs went about resolving such incidents. In total, Dr. Norscia and his team studied the details of 216 pig conflicts over the course of six months.
Some pigs tend to be attackers; others tend to be victims. Who is what depends largely on weight, for, among pigs pounds mean power. The attacker might bite, kick, bump or lift the victim (or string together a sequence of those actions). Most conflicts ended in seconds, but some lasted a minute or two.
In most animal species that would be that. However, many of the pig conflicts Dr. Norscia observed had interested parties beyond the protagonists (主角). He therefore wanted to understand the role of these bystanders in resolving fights-and what this says about pigs' cognitive (认知) abilities.
Since there was usually not enough time for a bystander pig to intervene during the heat of a conflict (though this did occur), he and his colleagues looked at what happened in the three minutes directly following an aggressive interaction. Sometimes, they found, the protagonists made up on their own—for instance, by touching noses.
On other occasions, though, a third pig stepped in. Sometimes this bystander acted as a peacemaker, engaging with the attacker and reducing the number of subsequent attacks compared with what might otherwise have been expected. Sometimes, by contrast, the bystander engaged with the victim. This appeared to calm the victim down, for it reduced anxiety-related behavior such as shaking and scratching.
