Home > A. Habilis: habit, hand, and how we learned to speak > Near People–Bottlenose Dolphins and Others

Near People–Bottlenose Dolphins and Others

File:Tursiops aduncus, Port River, Adelaide, Australia - 2003.jpg


It’s been a while since RT has posted on the development of the human brain. RT is thinking in particular of his Habilis thread, which mentions the role of our hands in the development of thinking: the making of stone tools preceded the first spoken words by about a million years, so it seems likely that the first lithic industry shaped both our thoughts and words.

Not so with bottlenose dolphins. Here is a creature whose ancestors disappeared into the ocean 50 million years ago. RT cannot help but remember our own ancestors leaving the tropical forest (only about 8 million years ago). Could it be that changes in fundamental environment trigger brain growth as a species learns to cope with its new surroundings? Furthermore, could the difference between dolphin and human intelligence depend largely on the usefulness of their limbs?



At right we have models of the brains of three different animals: from left, a wild pig’s, a bottlenose dolpin’s, and a human’s. The relative size of a human and dolphin’s brains can be difficult to determine: the encephalization quotient (EQ) of human’s is far greater than the BND’s (7.44 vs. 4.14); on the other hand, the absolute brain mass of the BND slightly exceeds that of humans’ (1500-1700 vs. 1300-1400 grams), and the BND’s brain is more convoluted than ours is. Another consideration is the degree that the brain grows after birth: a human is born with a brain 28% of its adult weight; a dolphin, with a brain 42.5% of its adult weight.

Finally, dolphins possess a large brain structure missing in humans: the paralimbic lobe. Neurologists connect this structure to the regulation of sensation, emotion, and social interactions. Could the BND be social in some way that we are not?


So here is a plausible reading of what we know so far: a bottlenose dolphin has the second-largest brain in the animal kingdom, but its brain nonetheless trails the size of our brain significantly. But then that dread enforcer of the truth shows up: a question (or a whole gang of them!)…does the size of the brain have anything to do with complexity of function and mental experience? …how, as a matter of fact, do we measure the brain’s complexity? …is there anyway of knowing what it is that a dolphin’s brain does? …Or what the inner life of a dolphin is like?


In a previous post, RT listed the mental abilities the primates, cetaceans, and smaller-brained animals possess. The list is impressive, but being focused on function, does not answer the question of inner life–what kind of mind do bottle-nosed dolphins have? Looking at human consciousness, we might divide our own mental life as follows:

Human mental activity

1) maintaining automatic physical activities such as respiration and heart function;

2) experiencing our immediate environment and generating emotions and other automatic responses to the things we sense;

3) imposing control on our environment at a primate-level: establishing a territory, creating and maintaining a social hierarchy and relationships generally;

4) communicating between ourselves in a more precise way via language and the total mental experience it conveys; creating sophisticated tools that expand and refine our control of the environment;

5) generating and manipulating abstract concepts to solve problems via mathematics and logic; and

6) maintaining overall control and harmony of our minds through artistic activities such as music and poetry;

How many of these abilities do dolphins share?

Items 1-3, certainly. There is plenty of evidence for the basic physical and emotional functions, as well as a rich social life, in BNDs. Readers should also note that BNDs pass the self-recognition test and even use individualized signature whistles to identify themselves–suggesting that they have personal names.

A further consideration is the active sex life of the BND; many researchers connect sexplay in animals generally with higher levels of intelligence.

Item 4, maybe. Like us, dolphins seem to have basic units of mental communication–in our case, words and sensory experiences; in theirs, clicks, whistles, and images of their surroundings generated by echolocation. It has been shown that BNDs use some of this sound information to construct mental images of their surroundings. Could it be that BNDs are capable of altering and manipulating these images to convey comments and even full language? Since humans have used artificial languages to communicate (at a low level) with dolphins, it’s clear that BNDs can learn syntax and grammar.

Item 5, probably. The ability to create 3-D mental images argues for a powerful understanding of space and volume in BNDs–and, by extension, an advanced grasp of number.

Item 6, probably. Dolphins are great singers and dancers. An early researcher reported receiving a powerful, controlled, multi-frequency sound burst from a dolphin that made him feel completely aware of the physical structure of first his head and then his body–almost like he was being scanned to create an image. This is communication at its most physical, precise, and intense. Could it also be part of a medical diagnostic? Many anecdotes suggest that dolphins are capable of moral behavior.


In light of these intellectual similarities, RT would like to suggest the creation of a legal category–near people. Other animals that RT would include as near people–bonobos, gorillas, and chimpanzees. Near people would be entitled to protected environments, and killing them would be legally forbidden across the globe. Additional funding would be devoted to studying and understanding near humans.

We cannot afford to let near people go extinct–they have too much to teach us about the mind and ourselves. Do we really want to kill an animal that gave itself a name at birth?



Photos: top: Tursiops aduncus, WikiCmns; CC 1.0 attribution; Author: Aude Steiner. bottom: WikiCmns; CC 1.0 attribution; Author: Boksi.


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  1. September 22, 2013 at 3:52 am

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