human

Humans are the most common and widespread species of primate, and the only extant species of the genus Homo. They are great apes characterized by hairlessness, obligate bipedality, manual dexterity with opposable thumbs, precision grip, and high intelligence. Humans have large brains compared to body size, enabling more advanced cognitive skills that facilitate successful adaptation to varied environments, development of sophisticated tools, and formation of complex social structures and civilizations. Humans possess a disproportionately larger volume of both cerebral white matter and gray matter present in the prefrontal cortex (PFC) than any other primate species, which facilitated the expansion of higher-order executive functions.