Discovery: whale songs follow the structure of human languages 🐋

Human languages follow a surprising law: the most frequent word is used twice as often as the second, three times as often as the third, and so on. This regularity, called Zipf's law, has just been discovered in an unexpected domain: humpback whale songs.


An international team, led by researchers from the Hebrew University of Jerusalem, the University of St Andrews, and the University of Edinburgh, analyzed eight years of humpback whale song recordings from New Caledonia. Their study, published in Science, reveals that these songs exhibit the same frequency distribution as observed in human languages.

The scientists applied techniques inspired by language learning in human infants to decipher whale songs. These marine mammals, like humans, learn their communication system culturally, by imitating their peers.

This discovery raises a question: why do two species so evolutionarily distant share similar communication structures? The researchers suggest that cultural learning is at the origin of these similarities. Communication systems that are difficult to learn do not survive intergenerational transmission.

The statistical properties of whale songs, similar to those of human languages, facilitate learning. This statistical consistency, combined with a Zipf distribution, appears to be a universal characteristic of culturally transmitted communication systems.

Does this mean that we will one day be able to communicate with whales? Unfortunately, no. This study does not allow us to understand the meaning of whale songs. As in instrumental music, structures can be learned and repeated without conveying a specific message.

The researchers predict that this Zipf distribution should be found in other culturally transmitted communication systems, such as bird songs. This work opens new perspectives on cultural evolution and animal communication.

What is Zipf's law?

Zipf's law is an empirical observation that, in a text corpus, the frequency of a word is inversely proportional to its rank in the list of most frequent words. In other words, the most frequent word appears twice as often as the second, three times as often as the third, etc.

This law applies to a wide variety of phenomena, ranging from word frequency in natural languages to website popularity. It reflects a natural tendency towards efficiency in communication and information organization.

The discovery of this law in whale songs suggests that the underlying principles of effective communication could be universal, transcending species barriers and modes of communication.

How do whales learn their songs?

Humpback whales learn their songs culturally, by imitating the sounds produced by their peers. This learning process is similar to that observed in humans, where infants learn to speak by listening to and imitating adults.

Whale songs are complex and vary among populations, indicating cultural transmission of these behaviors. Whales can modify their songs over time, introducing new sequences while retaining certain basic structures.

This capacity for learning and innovation in communication suggests a high level of cognitive sophistication in whales, comparable to that of humans in some aspects of communication and culture.