Why do we always think other animals are so simple?
There is a new study out from the University of Michigan which concludes that paper wasps are capable of behavior that resembles logical reasoning. The research shows for the first time that a nonvertebrate animal can use transitive inference, which is a form of logical (or deductive) reasoning. that allows one to derive a relation between items that have not been explicitly compared before. Many of us may be familiar with this from various tests and logic problems: If Ann is taller than Katy, and Katy is taller than Julie, then Ann is taller than Julie.
Sherlock Holmes is famous for his use of deductive reasoning; and indeed, for millennia, transitive inference was considered a hallmark of human deductive powers, note the authors. Why we didn't assume other creatures could also do this is so very human of us – we have had a hard time understanding that animals show their intelligence in different ways. But that's another story. (And it's one that you can conveniently read right here: Animals are smarter than most people think.)Anyway, back to the wasps. Previous research tried to determine if honeybees could demonstrate transitive inference – and they could not, or at least as far as the researchers could tell. Which led University of Michigan evolutionary biologist Elizabeth Tibbetts to wonder if paper wasps' famous social skills could enable them to succeed where honeybees had stumbled.
The researchers set up some experiments for two species of paper wasps, Polistes dominula and Polistes metricus, to see if they could figure out a transitive inference problem. You can read about the methods here, but I will just cut to the chase with these takeaways.
1. They trained the wasps to discriminate between pairs of colors, and the wasps learned to do this quickly. (Did you know that wasps could be trained?)
"I was really surprised how quickly and accurately wasps learned the premise pairs," said Tibbetts, who has been studying the behavior of paper wasps for two decades.
2. The wasps were able to organize information into an implicit hierarchy and used transitive inference to choose between novel pairs, Tibbetts said.
"I thought wasps might get confused, just like bees," she added. "But they had no trouble figuring out that a particular color was safe in some situations and not safe in other situations."
"This study adds to a growing body of evidence that the miniature nervous systems of insects do not limit sophisticated behaviors," said Tibbetts.
Meanwhile, paper wasps are obviously excellent architects and builders: They make their own supplies by mixing dead wood and plant stems with saliva to construct water-resistant, ant-repellent nests with fabulous curb appeal.
And that's not all. Previously Tibbetts – who I know think of as the wasp whisperer – published a paper showing that paper wasps recognize individuals of their species by variations in their facial markings; in other research she and her colleagues found that have surprisingly long memories and base their behavior on what they remember of previous social interactions with other wasps.
They may not have invented the Internet or built spaceships that can take photos of Mars, but they've got some pretty good tricks up their little wasp sleeves. And hey, they're not utterly decimating their environment like some animals are doing, so who's really the smart ones here anyway?
For more, you can read the paper in Biology Letters.