What Makes Us Human?

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What makes us human? For thousands of years, we have struggled to describe what it means to be human. Is it the way we walk, the size of our brain, the tools we use, or our capacity for emotion? All of these can make a difference when it comes to understanding our ancestry and what makes us special. Brain size is a determining factor in the intelligence of a species. Many people would think that the larger the brain, the smarter the species; however, a species can have very large brains and bodies to match. Because of this problem, we use a ratio called the encephalization quotient (EQ) to accurately measure “how ‘brainy’ an animal is for its body size” (Walker 216). An EQ value ranges from 1 to 12. The EQ of a chimpanzee is anywhere from 2 to 4, while that of a modern human is anywhere from 5 to 10 (Walker 216). This may not seem like a very large difference, but there are distinctive qualities that make human brains superior. For example, the cortex, known as the “seat of intelligence” is responsible for where memories and senses are stored to be utilized (Campbell 84). The cortex of a human brain makes up about 80% of its volume, while the cortex of a chimpanzee brain makes up about 75% of its volume (Campbell 84). This is where the difference between humans and other animals, including chimpanzees, lies, and it is because of this that we have the “ability to look inward and observe our own mental processes: Humans not only think but know they are thinking.
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