How Are Large Mammals' Brains Different Than Humans' Brains?

Many large mammals, such as whales, dolphins, chimpanzees and elephants, have enormous brains--much larger than humans. Yet the human brain functions differently from the brains of other large mammals. Modern brain studies reveal the human brain's unique qualities.

  1. Brain Size

    • For years, brain studies focused on brain size and the relation size has to intelligence. If brain size dictated intelligence, the whale swims as the most intelligent creature on the planet. Whales have the largest brain of any mammal. Also, elephants and dolphins have larger brain mass than humans. However, behavioral studies do not rank these mammals as more intelligent than mankind because, according to professor Brian Hare at Duke University: "...intelligence is not very well linked to brain size."

    Proportional Weight

    • Humans have a higher brain-to-body-weight proportion than other large animals. In other words, the whale weighs more and has a physically larger brain, but proportionally, whales' brains comprise .01% of their mass while human brains take up 1.9% of body weight. Humans have more brain, pound for pound, than the larger whale. Porpoises rank second to humans in brain portion to body weight. Elephants have proportionally smaller brains than humans. For our size, the human body has more brain, proportionally, than other mammals.

    Layered Neocortex

    • According to Science Daily, the brain's neocortex "... is involved in higher functions such as sensory perception, generation of motor commands, spatial reasoning, conscious thought, and in humans, language." Although the dolphin has a larger neocortex than humans, the deeper layers of the human brain makes it more compact and efficient in its communication with other parts of the brain. The difference in the layered, deeply-grooved human neocortex produces consciousness that other large animals lack.

    Inner Wiring

    • Chimpanzees, dolphins and humans have convoluted, layered and sectioned brains, when compared to the smooth surfaces of other large mammals. Primates all have "big frontal lobes, necessary for social interactions, language, and cognition," The Human Genome website states. According to the American Museum of Natural History, chimpanzee and human brains share "language-related structures." However, the human brain seems wired like no other large mammal's. A larger "angular gyrus" distinguishes humans from chimps. The gyrus synthesizes information from various senses and combines information with symbolic language. Abstract thought remains the crowning achievement of the human brain.