Humans are a profoundly social creature. We share rich social qualities with many other species. Where we differ is in our ability to build upon cultural information in a cumulative manner, supported by complex forms of cooperation and language.

Studies of tool use show that humans have distinct abilities to think metaphorically, seek out and learn from the most skilled craftspeople, and produce innovations in technologies that are themselves evolutionary in nature. Research exploring early childhood development shows that we are avid social learners who “over-imitate” the actions of adult mentors, picking up functionally opaque actions and repeating them so that we behave like our instructors. We also possess cooperative norms and engage in complex ritual practices that need not have any obvious beneficial purpose. This allows us to form group identities and deepen emotional bonds with others in our communities. Cultural evolutionists study both human and animal cultures, and conduct comparative experiments and theoretical analyses to try to understand in which respects human cognition is unique and how our cultural capability evolved.

What makes us "human"?

Our evolutionary history is one of gradually building up the capacity for symbolic communication, culminating in language. That capacity to express ourselves symbolically impacted other cognitive and social domains too. For instance, sometime 100,000 to 200,000 years ago, our ancestors gained the abilities to create abstract art in jewellery and figurines, ornamentation on weapons, and paintings on cave walls. There is now clear evidence that languages themselves evolve as, for instance, words or phrases that are difficult to learn or rarely used get lost, whilst effective and familiar terms are retained.

The human story is one of being a social animal whose life is shaped profoundly by an ancient trade-off between large brains and standing upright on two legs. The limiting factor here was the pelvis of mothers who must successfully pass large-headed infants through the birth canal with both parent and child surviving the ordeal.  Cultural evolutionists contribute to the reconstruction of this history, through archaeological, psychological and linguistic investigations.

Where have we come from, and why are there different populations?

Our earliest ancestors come from a large swath of eastern Africa where they left footprints in volcanic ash, cast their tools (and a few skeletons) into the bogs to be preserved, and left a variety of relatives who each in their own way can be called an early human. Yet it is not currently understood what gave rise to Homo sapiens as a distinctive ancestral line with rich conceptual abilities, arts and language, and sophisticated tools that enabled them to find cultural adaptations in environments where genetic adaptations alone would limit their survival.

Cultural evolution contributes to an understanding of human diversity. Some differences between humans are genetic: for instance, some people have blue eyes and light skin colour because for roughly 10,000 years, their ancestors lived at high enough latitudes that the change in hue increased absorption of vitamin D. Other differences between individuals, such as diet or fashion, are cultural in origin. However, culture has also affected genetic evolution. For instance, some populations domesticated cattle and consumed dairy products, which led them to evolve genetically to be composed of people who can digest lactose in milk as adults, giving them distinct survival advantages when other food supplies were scarce. The field of cultural evolution seeks to understand how the behaviour, traditions, technology and cognition of human populations differs, and how these differences affected genetic evolution.

Where are we now?

Most dramatically, we humans have grown in numbers to almost 8 billion people who live in every niche imaginable. Cultural evolution provides adaptations that enable us to thrive in these places. While there are special genes for oxygen absorption among populations who live at high altitudes, humans could not live in such environments without cultural adaptations such as warm clothing, fire and domesticated species such as yak. Similarly there are cultural traits for passing owned property from father to son, or mother to daughter, in social institutions that are well suited to their landscapes and unique ecological needs.

Particularly importantly given our current environmental crisis, we have under some conditions developed institutions for sustainably managing our natural resources, despite flagrantly exhausting their potential under other conditions. Similarly, our ethnocentric biases – favouring people who look or sound like us – appear to be quite flexible, which is relevant to tackling the epidemic of parochialism and intercommunity conflicts in recent times. Understanding how and why the differences between human societies arise is a core aspect of the field of cultural evolution, and the knowledge generated can help societies to find practical solutions to pressing ecological and social challenges.

The human story is richly diverse and deeply inspiring. Members of the Cultural Evolution Society are actively involved in improving our collective understanding of this amazing story.

Discover more about the human story in A Story of Us by Lesley Newson and Peter Richerson, as well as other resources listed on our Discover more page.