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Are Birdsongs Language?

Michael Egnor

Poephila_acuticauda_-_Bird_Walk.jpg

Atheist mathematician Jeff Shallit insists that animals have language. He cites several studies, including a study on birdsongs, reported on in New Scientist, that claim to detect grammar in the songs.

Let’s take a look:

First evidence that birds tweet using grammar

They may not have verbs, nouns or past participles, but birds challenge the notion that humans alone have evolved grammatical rules.

Bengal finches have their own versions of such rules — known as syntax — says Kentaro Abe of Kyoto University, Japan. “Songbirds have a spontaneous ability to process syntactic structures in their songs,” he says…

In the wild, Bengal finches call back vigorously whenever they hear unfamiliar songs, usually from intruding finches. In the lab, Abe and colleague Dai Watanabe of the Japan Science and Technology Agency in Saitama exploited these reactions to gauge whether finches could notice “ungrammatical” songs.

The rules

First, they played finches unfamiliar songs repeatedly until the birds got used to them and stopped overreacting. Then they jumbled up syllables within each song and replayed these versions to the birds.

“What we found was unexpected,” says Abe. The birds reacted to only one of the four jumbled versions, called SEQ2, as if they noticed it violated some rule of grammar, whereas the other three remixes didn’t. Almost 90 per cent of the birds tested responded in this way. “This indicates the existence of a specific rule in the sequential orderings of syllables in their songs, shared within the social community,” Abe told New Scientist.

In subsequent experiments Abe showed that the rules were not innate — they had to be learned. Birds raised in isolation failed to react to SEQ2 until they had spent two weeks with other birds. He also taught birds unnatural grammatical rules by habituating them to one of his jumbled versions, then gauging their reactions to remixed versions that violated the “artificial” rules.

When birds sing, is their song a language, with grammar and syntax? Let’s review what we mean by language and grammar.

A sign is an object or an event that points to something other than itself. Signs are either signals or designators.

Signals are events that point to a proximate object. There is a tight link, physically and temporally, between a signal and its object. Smoke is a signal of fire. A thundercloud is a signal of impending rain. A fire bell is a signal of a fire in the building.

Designators are things (for our purposes, words) that point to an object that is not physically nor temporally linked to the word. “Cat” is a designator for the animal of that name. But the word “cat” isn’t physically or temporally related to a cat. It doesn’t look like a cat and it isn’t necessarily near any cat. The word “cat” is not a signal. It’s a designator — a word.

Words are abstract signs, whereas signals are concrete signs.

Language is comprised of words, not of signals. Smoke rising from a fire (a signal) is not a language. A thundercloud signaling rain is not a language. A referee signaling a touchdown or raising the hand of the victorious boxer is not engaging in language. They are signaling.

Writing or saying “the smoke rose from the fire” or “Ali beat Frazier” is language. It is the abstract nature of words — the conceptual but not physical link between the word and the object — that makes words, but not signals, the bricks of language.

The next issue is complexity and grammar. Signals can have complexity — there is theoretically no limit to the complexity of a signal. The mathematical description of the smoke rising from a fire may be extraordinarily complex. But signals don’t have grammar, regardless of complexity.

Grammar is a rule-based framework on which words are arranged. All human grammar (and all grammar is human) is a metaphysical template on which words are hung. By metaphysical, I mean that the elements of grammar — nouns and verbs and adjectives and predicates and the like — categorize words metaphysically. Nouns (grammar) are substances and particulars (metaphysics). Verbs (grammar) are identity or change (metaphysics). Adjectives and predicates (grammar) are universals (metaphysics). Grammar maps words to reality by imposing a metaphysical structure on language. “Mary ages gracefully” is grammatically correct because it is metaphysically coherent. A substance (Mary) changes (ages) in accordance with a universal (grace).

Grammar is a deep structure that maps language to reality. It is, as Chomsky has noted, inherent to man. We are born with the capacity for grammar — it is not learned by either imitation or instruction. Grammar, like language, is in our soul, so to speak.

Do birdsongs have grammar, as these researchers have claimed? There is no reason whatsoever to infer that. Wild finches call back vigorously to unfamiliar songs, presumably because it may be a territorial intrusion by another bird. The birdsongs are obviously signals — signs pointing to proximate objects. The birds aren’t voicing outrage at the intruder’s violation of bird property statutes. The birdsongs are signals, voiced by animals to establish territory and warn intruders. The songs are an alarm, not a speech.

The researchers trained the birds to ignore intruder songs, and then jumbled the songs of the putative intruders in four different ways. In one of the ways, the birds again became agitated, suggesting that that particular variant of the song again was interpreted as signaling intrusion.

The researchers concluded that this represents a change in grammar which the birds recognized as language, but there is nothing here that suggests grammar or language. Signals can be very specific and very complex, and specificity and complexity alone do not denote grammatical structure. For example, the harmonics of a fire alarm are quite complex and the pitch may be quite specific. If the pitch and amplitude of the fire alarm are changed, so it’s a low hum instead of a high-pitched clang, it may no longer sound like an alarm, and people may no longer evacuate the building when it rings. But that does not mean that the ‘grammar’ of the fire alarm has changed. The signal has changed. There is no grammar in a signal.

If you want a deeper sense of the quality of the science in this study, consider this:

Finally, Abe chemically destroyed an area of the brain called the anterior nidopallium in some birds, and was thereby able to demonstrate that it is vital for registering faulty grammar. In humans, a region called Broca’s area is activated when we hear ungrammatical sentences, so Abe suggests that studying the counterpart region in finches might throw new light on the origins of human grammar.

The nidopalluim in the avian brain is the region that subserves executive function in the bird. It is analogous to layers II and III of the human cortex, which are areas damaged in patients in a persistent vegetative state (e.g., Terri Schiavo).

The researchers induced brain damage in a region of the avian cerebrum that correlates with persistent vegetative state in humans, and concluded that the birds lost their understanding of grammar.

From the article:

“It’s an ingenious experiment showing that birds are sensitive to changes in song that are consistent with different grammars,” she says. “More and more, we are seeing similarities between humans and animals, and that makes some people uneasy.”

“Ingenious.” Except for the experimental design and conclusions drawn, which are witless. We are not seeing any new similarities between humans and animals. There are many real similarities between humans and animals, well established, but there are no similarities in language or abstract thought, which are abilities restricted to man.

I am uneasy, though, about very bad science.

Photo credit: JJ Harrison (Own work) [CC BY-SA 3.0], via Wikimedia Commons.

Michael Egnor

Senior Fellow, Center for Natural & Artificial Intelligence
Michael R. Egnor, MD, is a Professor of Neurosurgery and Pediatrics at State University of New York, Stony Brook, has served as the Director of Pediatric Neurosurgery, and award-winning brain surgeon. He was named one of New York’s best doctors by the New York Magazine in 2005. He received his medical education at Columbia University College of Physicians and Surgeons and completed his residency at Jackson Memorial Hospital. His research on hydrocephalus has been published in journals including Journal of Neurosurgery, Pediatrics, and Cerebrospinal Fluid Research. He is on the Scientific Advisory Board of the Hydrocephalus Association in the United States and has lectured extensively throughout the United States and Europe.

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