Some dogs can understand 250 words.
Dogs are man’s best friend, and the canine ability to understand human words has gone a long way to solidify that world-changing relationship. According to the American Psychological Association, the average dog can understand 165 words, and “super dogs” — those in the top 20% of canine intellect — can understand around 250 words. Dog intelligence can be divided into three main types: instinctive (what the dog is bred to do), adaptive (what a dog learns from its environment), and working/obedience (what a dog is trained to do). Research into the levels of working/obedience intelligence in various dog breeds shows that border collies displayed the highest levels, followed by poodles, German shepherds, and golden retrievers. With the ability to also understand simple math (1+1 = 2, for example), these “super dogs” have an estimated cognitive ability of 2- to 2.5-year-old humans.
Although an understanding of 250 words is already impressive, it’s by no means the absolute limit. The Einstein of the dog world is a border collie named Chaser. According to the journal Behavioural Processes, Chaser had the ability to recall and correctly identify 1,022 words. This far exceeds the vocabulary of any known dog, and pushes Chaser into the cognitive ability range of a 3-year-old. Now, that’s an extremely good girl.
Not all language is verbal, and scientists theorize that human language actually evolved from a gesture-based language in our species’ distant past. A study published in the journal PLOS Biology in 2023 analyzed the gesture-based language of chimpanzees and bonobos, the closest living relatives to humans. In the study, thousands of humans (5,656 to be precise) watched videos of chimpanzees and bonobos striking different poses, and the human study subjects were often able to correctly guess the pose’s meaning (the meanings had been predetermined by researchers based on work with the apes). Participants were correct slightly more than 50% of the time in a series of four-answer multiple-choice questions. The results suggest that humans retain an innate ability to understand at least some of the language of great apes, which includes call signals that may be precursors to our own language.
