According to a new study, crows possess the cognitive ability for one of the linguisticelements that make human language so complex.
In the early 2000s, Noam Chomsky and other linguists thought that if there was one thingthat belonged specifically to human language, it was recursion, and that this was whatdistinguished human language from animal communication. As it turns out, this is not thecase: a 2020 study proved that rhesus monkeys can do the thing too, and a newly publishedstudy shows that crows can also do recursion.
OK, so what’s recursion? It’s the capacity to recognize paired elements in larger sequences –something that has been claimed as one of the key features of human symbolic competence. Consider this example: “The rat the cat chased ran.” Although the phrase is abit confusing, adult humans easily get that it was the rat that ran and the cat that chased.Recursion is exactly this: pairing the elements “rat” to “ran” and “cat” to “chased”.
Put somewhat more simply, similarly to humans monkeys and crows can recognize that astructure can contain other structures with meaning. But for decades scientists thought thathumans, or at least primates, are the only animals capable of understanding recursion. Yet,following the discovery, about two years ago, that rhesus monkeys can understand the ideaof recursion on a par with three- to four-year-old human children (albeit with some extratraining), a team has now conducted similar experiments with crows, and they turned out tooutdo monkeys in certain aspects!
Researchers from the University of Tübingen have studied crows using the same method astheir colleagues used in the previous Wisconsin study with monkeys. In this one, the animalshad to find a pair of symbols in a sentence of symbols, so they had to find out, for example,where in the <()> symbol sequence the pair of brackets was located.
When they did, the researchers created longer and longer sentences to see if the testsubjects would still pick out the embedded ones.
As with the rhesus monkeys, the subjects could pick out the embeddes characters in 40% of trials, but without the extra training that the monkeys received!
So, recursive capabilities are not liited to primate genealogy, as it turns out. Which also helps reiterate just how smart crows are.
source: earthlymission.com
