Humans (''Homo sapiens'', meaning or ) are the most abundant and widespread species of primates, characterized by bipedalism, minimal body hair, and large, complex brains enabling the development of advanced technology, culture, and language. Humans are highly social beings and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Curiosity and the human desire to understand and influence the environment have motivated humanity's development of science, philosophy, religion, mythology and other fields of knowledge. Humans have a large and highly developed prefrontal cortex, the region of the brain associated with higher cognition. They are intelligent beings, capable of episodic memory, flexible facial expressions, self-awarene ...