As researchers delve deeper into the cognitive abilities of animals, a fascinating question arises: Can they truly understand human language? This inquiry goes back to the early 20th century, exemplified by the case of Clever Hans, a horse that captivated audiences throughout Germany with his apparent ability to solve mathematical problems and perform various tasks. However, investigations revealed that Hans was responding to subtle, subconscious cues from his trainer, debunking the myth of his intelligence.
Fast forward to today, and the exploration of animal understanding of language has only intensified. Studies conducted in the 1960s and 70s ignited interest in how various species comprehend human communication, though skeptics pointed out that many animals seemed to mimic their trainers rather than grasping the meaning behind words.
Take Koko, for example, a female western lowland gorilla who died in 2018. Koko learned around 1,000 signs and could respond to over 2,000 words spoken in English. However, critics caution against viewing her as fluent in American Sign Language, arguing that her signing often lacked coherence and relied heavily on her trainers’ interpretations. Simon W. Townsend, a professor of evolutionary anthropology at the University of Zurich, notes, "Humans are special in many ways, and certainly language is unique to humans, but I think we’re finding that there are really quite some similarities between the communication systems of animals and humans."
Among animals, the title of the most advanced language skills belongs to Kanzi, a male bonobo who lived from 1980 to 2025. Unlike Koko, Kanzi communicated through a lexigram board with approximately 200 symbols representing objects and concepts. Townsend, who studied Kanzi, describes his skill as a step toward a more profound understanding of human language. He stated, "He’s learned symbolic communication, which is a feature of another species’ communication system." Kanzi’s proficiency extended beyond symbols — he understood some spoken English, successfully following commands with an impressive accuracy rate.
A pivotal study in 1993 found that when presented with novel sentences like, "Put on the monster mask and scare Linda," Kanzi could complete the tasks about three out of four times. This level of comprehension hints at significant cognitive abilities, though skepticism remains about the depth of his understanding of syntax and grammar.
Shifting gears to a more modern context, dogs have developed a unique rapport with humans over thousands of years. These canines exhibit natural inclinations to respond to human voices and gestures as early as eight weeks old. Federico Rossano, an associate professor of cognitive science at the University of California, San Diego, has been exploring the linguistic capabilities of dogs, studying how they respond to the sounds of words rather than just contextual cues.
In 2024, Rossano conducted research involving 59 dogs that listened to recordings of words associated with activities like "outside" and "play," alongside a nonsensical term for comparison. Interestingly, when the dogs heard "outside" or "play," many of them exhibited behaviors related to going outside or playing, indicating a level of understanding that transcended mere context cues.
Rossano warned that while these findings are promising, dogs also struggle to differentiate words that vary by even a single sound. This limitation highlights ongoing debates about the extent of their language comprehension. Comparisons with other supposed communicative feats in dogs, such as those seen with viral Instagram-famous pets using buttons, are not the focus of Rossano's research; he is prioritizing foundational questions of understanding and cognitive processes. Reflecting on his initial skepticism, Rossano remarked, "Maybe there's more of a mind there than we give them credit for."
In a surprising twist, researchers have even discovered that humpback whale song bears striking similarities to human language structures. Dr. Jenny Allen, an expert in whale song structure at Griffith University, spent years studying the nuances of these melodies. These findings raise new questions about the cognitive abilities of whales and their capacity to understand complex sound patterns—a depth of comprehension that could mirror elements of human language.
This extensive exploration across various species—from the clever gestures of bonobos to the responsive barks of dogs, not to mention the lyrical calls of humpback whales—leaves us wondering where the boundaries of animal communication truly lie. Each discovery enriches our understanding of the animal kingdom and reflects the shared connections that bind us across species. As research progresses, one undeniable conclusion emerges: Animals possess remarkable capacities for communication, and perhaps they have more wisdom and understanding than we previously assumed.
