Homo sapiens

Humans (Homo sapiens, meaning 'thinking man' or 'wise man') are the most abundant and widespread species of primates, characterized by bipedality, hairlessness, 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-awareness and a theory of mind. The human mind is capable of introspection (meta-cognition), private thought, imagination, volition and forming views on existence. Humans can also mentally travel through time (chronesthesia) which signifies episodic foresight. These attributes have allowed great technological advancements through reason and the transmission of knowledge to future generations. In cultural anthropology, the cumulative preservation and advancement of knowledge across generations is known as the Ratchet Effect.