This image shows the similarities between our human brains and the brains of our ancestors. However, it's the differences in our neural makeup that makes us such a unique species. As an infant, the human brain actually resembles the primate brain quite closely, but as we grow and are shaped by our environment, the brain rewires to adapt new skills and patterns of thought. The part of our brain responsible for higher thought functions—the cortex—contains more neurons than any other animal on the planet (16 billion of them!) which enable us to synthesize much more advanced connections within our brain. It's these innumerable connections that makes our minds uniquely human.