What makes us human? Many of the characteristics commonly listed as ‘uniquely human’, are in fact, upon closer inspection, NOT. We are not alone in our use of tools, language or a notion of self. We are not unique in our bipedal stance, our opposable thumb or our intelligence. Our societies seem simple and crudely constructed when compared to those of a bee or a termite. Perhaps there is one thing left, however, that is truly human – art. Surely culture, art and religion are something only humans have constructed? And if that is the case, what is it about humans that led us and only us, to create such a rich array of art and ritual, which appears, in evolutionary terms, to be superfluous to our survival?

Before we can discuss whether culture is truly a human phenomenon, we must first define what we mean by culture. The modern understanding of the word ‘culture’ (in reference to art and behaviour, as opposed to cultivation) emerged only in the 20^th century, and the Oxford English Dictionary provides two definitions for this meaning of culture:

1. The arts and other manifestations of human intellectual achievement regarded collectively – a refined understanding or appreciation of this
2. The customs, ideas and social behaviour of a particular people or group.

So, even our dictionary definition makes the implicit assumption that culture is a human construct. Most discussions of the idea of culture, however, highlight one key aspect, which may not in fact be unique to humans; the form of transmission of culture is key. Culture is non-genetic. It is passed from generation to generation by learning and there is variation in culture between groups from different regions.

When viewed in this way, the early seeds of culture are evident in some primates and other animals. In chimpanzees, simple tool use enables individuals to access a new food source – coula nuts. Chimpanzees are able to open the shell to reach the nutritious inside by hammering the nut against a naturally occurring anvil. Young chimps are taught this behaviour and it takes some time to learn the technique. And even closely related groups, sharing the same habitat, show differences in their hammer-choices. Some groups prefer stone hammers, others wood, others still use each type of tool at a different time of year. These differences are independent of genetic differences, and independent of different habitat requirements. They are the result of culture – individuals learn from their elders and, in a rather elaborate game of Chinese whispers, different groups develop different techniques and stick to them.

Culture and Learning

A similar phenomenon occurs in songbirds. Birds which produce song are distinct from those that simply produce calls, and songbirds have a highly developed vocal organ which enables them to produce diverse and elaborate songs, which are usually used territorially. Bird song is learned in a two-step process. Young birds begin by listening to the song produced by their parents or close neighbours, and later they begin to try and imitate it. Exposure to the song is essential to this process, and birds reared in isolation fail to develop a complete song as adults. This indicates that an individuals’ song is a learned component of their behaviour, and is not transmitted genetically (although the ability to learn the song almost certainly is). There is also substantial variation in bird song between groups of the same species, and regional dialects have been identified. The existence of this variation is likely to be beneficial as it enables individuals to identify group members from intruders. Therefore, the mechanisms that create this variation, the mode by which is it acquired, may have been subject to natural selection, even though the different variants of a particular song are not.

In fact, simple culture may be a by-product of teaching itself. As soon as information can be transferred from individual to individual, across generations, a new form of inheritance is created. The idea of the meme, first coined by Richard Dawkins, solidifies this concept. Information is subject to many of the same forces as genes are; certainly when information is transferred socially. Information, say the knowledge of how to crack a seed open, is stored in the brain of one individual, and can be passed on to other individuals verbally, or through some other form of communication. However, this information may not always be communicated faithfully, perhaps because of imperfections in the sending or receiving stage of the transfer, or in the translation of communicated information into binary information stored within the brain. Either way, social transmission of information is imperfect, and thus variation will be gradually introduced to the system. It is likely, however, that some variants of a particular piece of information (a meme), will be better and more useful to their owner, than others. Variants that are more successful may be more likely to be remembered, used, and passed down to the next generation. Thus over time there may be selection on different meme-variants within a population. Nevertheless, some meme-variants may be equally useful, or may be differentially useful, depending upon the environment in which they are placed. Populations living in different habitats, where the seeds available possess different characteristics, may find that slightly different seed-cracking memes may be applicable for different habitats. Thus variation in learned behaviour is created between different groups of individuals, and these differences are passed on throughout generations. This fits with out basic understanding of culture.

Thus, just as evolution and natural selection are unavoidable by-products of an imperfect (genetic) replication system and differential survival of individuals, culture, in it’s simplest form, may too be a natural consequence of the development of a (non-genetic) information transfer system such as language. Whenever there is imperfect transfer of information, and variable ‘survival’ of that information based upon some characteristic of that information, selection and variation will emerge.

So, despite what our dictionaries tell us, culture in itself is not a uniquely human characteristic. It is expected to emerge whenever there is transmission of information between individuals based upon learning. Culture may in fact be defined in this way, as the non-genetic transfer of information across generations. However, it is clear that, as with many traits which we would traditionally consider to be uniquely human, although simple forms exist outside humans, we have taken it to a whole new level. No animal has developed complex social rituals, art, religion or fashion. No other creature has quite the same appreciation for the aesthetic as we do.

The Emergence of Art

The debate continues as to when exactly in human evolution art first appeared. Much of this likely boils down to the fact that, even today, we struggle to define what exactly art IS. Nevertheless, there is now evidence that humans as far back as 80,000 years ago had primitive culture, religion, ceremonies and even art. In Blombos cave near Cape Town, South Africa, tools along with ochre have been found in association with early modern human remains. The ochre is believed to have been ground up and used for body decoration, which is suggestive of ceremonial behaviour. Furthermore, two pieces or red ochre, smoothed and carved with a crosshatch design, may be the earliest pieces of human art. That art appeared so early in human evolution is controversial, and uncontested evidence doesn’t appear for a further 40,000 years. Carved ivory figurines from Germany date to around 33,000 years ago, and are believed to have played both an aesthetic as well as a ceremonial role. They are heavily worn indicating that they played a central role in early human cultural life.

Cave paintings first appear around 35,000 years ago, in Northern Italy and France, and include depictions of humans and animals together. Advances in cave art can be seen in newer examples, such as the Lascaux caves in France, estimated to have been painted around 16,000 years ago. Again, these paintings include depictions of animals such as bulls, horses and antelope, but may also contain early representations of the night sky, suggesting that humans were starting to contemplate the world around them at a level beyond basic survival.

From 10,000 years ago, pottery and portable art proliferated, and the first appearance of sculpture occurred around this time. The bronze age brought further diversification in style, and brought with it the appearance of the first objects which had no obvious purpose other than art. Clearly, art was of paramount importance to these peoples, as to expend energy and materials to construct something of purely aesthetic appeal has no obvious survival value. To explain art in evolutionary terms is extremely difficult, however it may indicate the increasing importance of the social group to human survival, if art and religion played an important role in social group maintenance.

Throughout the history of human art, and even extending into modern times, religion appears to be a key component driving the creation of art. Religion is almost certainly a uniquely human trait. At least the external evidence of any kind of religion or spirituality is absent in non-human animals. The appearance of religious belief in humans may reflect a tipping point in our intellectual development; the ability to imagine and understand a distance future, and the development of truly abstract thought.

The Birth of Religious Thought

The first religion is thought to have emerged in the paleolithic, somewhere between 300,000 and 30,000 years ago. This is a pretty big window, and reflects the difficultly in both interpreting the purpose and meaning of early artifacts, and a difficulty in defining exactly what it is we mean by religion. Early evidence of ritualised burial, and ceremonial artefacts such as those found in the Blombos caves, may be indicative of early religious thought, but it is not clear. Religion encompasses multiple different thought processes, such as ritual, mythology and magical thinking, which may have appeared independently over a long period of time, eventually combining to form modern religious behaviour.

Ritualised and deliberate burial may indicate an appreciation for the dead that transcends daily life, and a concept of some form of after-life. The earliest undisputed human burial sites date to around 90,000 years ago, and coincide with the appearance of animal worship and certain animal cults such as the upper paleolithic bear cult, which performed ceremonial bear sacrifices, presumably for religious purposes. Later burial sites increasingly involve the use of red ochre pigment, which is believed to have had symbolic value.

Early religions did not take the form that we are now familiar with. Monetheistic religions, such as Judaism, Christianity and Islam, focussed around a single creator or deity, emerged as recently as 4,000 years ago. Prior to this, early humans believed in ghosts, spirits and animal worship was common.

What caused the emergence of religion? What was its importance to early human societies? And what is it about humans that lead us to construct such elaborate and abstract belief systems? One popular theory is that with developments in human intelligence, we attained a level of forethought unrivalled in the rest of the animal kingdom. But with this increased ability to plan for the future came an understanding and an appreciation of that future. An appreciation of death, and the fear that naturally follows that. Even Chimpanzees and other highly intelligent animals do not possess sufficiently sophisticated forethought to be able to conceive of death. The are unable to make the logical jump from the death of a neighbour to their own mortality. Once humans were able to do this, and their mortality became apparent, they needed something to explain this. Long-term memory and an improved ability to detect patterns in the world around them lead humans to appreciate more fully what a hostile world they lived in. And their new found understanding of death caused them to fear this. Religion provided a means of understanding the world around them, of explaining its hostility and coping with it. Furthermore, the concept of an afterlife would surely have comforted early modern humans who feared death. That ritualised burial is one of the earliest known forms of religion suggests that a deeper understanding of death may have been a primary force driving the development of religious thought.

Religion may be a natural consequence of the way in which our brains work. Naturally selected aspects of human cognition, such as our tendency to ascribe cause and effect to events and the modular nature of our thought processes may naturally predispose us towards religious thought. Religious ideas depart only a small amount from the natural world, which may permit our brains to accept concepts which cannot be proven. That the earliest forms of religion were based around more concrete entities such as animals, and the comparatively recent advent of more abstract deities may support this idea. Religion may have also provided an important tool for social cohesion. Social groups were clearly of tantamount importance to human survival, as they are for many primates. However, social group maintenance requires self-restraint and self-discipline, and religious belief may have aided early humans in achieving this. Rituals further aid group cohesion and social bonding, and may have been a key component of early religion.

Religion allowed early humans to make sense of the world around them, and enabled them to maintain long-term social groups which may have been essential to their survival. It allowed them to endure some of the consequences of their increased cognitive abilities and emotional and intellectual development . Behavioural and cognitive characteristics which were adaptive in many respects, as a side-effect caused humans to contemplate the world around them more carefully, and religion provided a comforting explanation for the hostility, stochasticity and suffering that they were now able to perceive so clearly.  Religious memes appealed to the way in which our brains work, and were readily transferred from individual to individual. Religion, at least in its earliest form, was adaptive and aided human survival. But a successful meme may be continued long after its usefulness has disappeared.

Finally, one last aspect of culture which can be considered to be uniquely human is the use of clothes. We are the only species who wears clothes. And we are certainly the only animal who has invented fashion. Dating the appearance of clothing in human evolution has been difficult, as the soft materials used are predisposed against long-term preservation. However, recent genetic analysis of human lice suggests that clothing may have been common place around 72,000 years ago. Body lice, which can survive only in areas covered by clothing, diverged from their common ancestor with more ancient head lice around this time, indicating that they were, for the first time, able to exploit a niche created by human clothing. What provoked the emergence of clothing is not clear however clothes may have been invented in order to cope with cooler climates as humans expanded out of Africa.

The appearance of jewellery is an indicator that clothes and body adornment had taken on a significance beyond simple survival, and that clothing was now playing a social role. Early beads have been found in Tanzania, dated to around 70,000 years ago. This suggests that fashion, or the use of body adornment for a social or religious purpose, appeared almost simultaneously with clothing. Other finds date to around this time, also. Shell beads in Morocco date to around 80,000 years ago, and show signs of pigment and prolonged wear. So, humans were wearing jewellery perhaps before they were wearing clothes. Certainly, the appearance of clothing and of a purpose for body adornment above mere survival seem to have occurred within a very short space of time. Jewellery may have been initially created as a means to signify group membership, or offering protection as a religious or spiritual tool.

So, finally we may have struck upon something that is truly unique to humans. Culture seems to have appeared to fulfil both a social and intellectual role, and may reflect the final increases in cognitive ability that marked the appearance of modern man. Although cultural transmission and regional variation in behaviour are not unique to humans, only humans have developed art, complex religious belief and ritual, and body adornment for social purposes. Only humans have imagined gods and an afterlife, and only humans have developed ritualised burial ceremonies. Animals can be coerced into producing art, and some even appear to display some level of creativity and enjoyment in producing art, but none have ever been discovered to do it of their own accord in their natural environment.

For many of the traits that are traditionally thought to be human, close inspection reveals that we in fact exist on a continuum. Language, tool use, and culture are not unique to humans. But we have taken them all to a level unrivalled in the animal kingdom. This suggests that humans are in fact not remarkable at all. Our success, our apparent uniqueness in the animal kingdom, is not the result of some special process. It is just the amplification of processes that exist throughout the animal kingdom, and throughout nature in general. We are the product of a specific set of selective forces, which have acted to varying degrees on all species. Language and sense of self emerge when social conditions require, and when and neurological conditions permit. Culture emerges as a natural consequence of non-genetic information transfer across generation. Religion and art appear when cognitive capabilities, selected for their benefits in other aspects of our life, require them. We are better tool users, better communicators and better empathisers than any other species. But we are not different. We are just a more extreme version of all of the rest of life on Earth.

Articles in this Series:

1. Part One: A Brief History
2. Part Two: Intelligence and Language
3. Part Three: Anatomical Adaptations
4. Part Four: Culture and Faith

Want to Know More?

• McBrearty and Brooks (2000) The revolution that wasn’t: anew interpretation of the origin of modern human behaviour. Journal of Human Evolution 39, 453 – 563
• Amati and Shallice (2007) On the emergence of modern humans. Cognition 103, 358 – 385
• Dawkins (1989) The Selfish Gene. Oxford University Press
• Slater (1986) The Cultural Transmission of Bird Song. Trends in Ecology and Evolution 1, 94 – 97
• Lynch (1996) The Population Memetics of Bird Song. Ecology and Evolution of Acoustic Communication in Bird
• Luncz, Mundry and Boesch (2012)Evidence for Cultural Differences between Neighbouring Chimpanzee Communities. Current Biology 22, 922 – 926
• Rappenglueck (2000) Paleolithic Timekeepers Looking at the Golden Gate of the Eclipitic; the Lunar Cycle and the Pleiades in the Cave of La tête du lion. Earth, Moon and Planets 85, 391 – 404
• Ice Age Star Map Discovered
• Conard (2003) Paleolithic ivory sculptures from southwestern Germany and the origins of figurative art. Nature 426, 830 – 832
• Hensilwood (2002) Emergence of Modern Human Behaviour: Middle Stone Age Engravings from South Africa. Science 295, 1278 – 1280
• Hinde (2003) Review of ‘In Gods we Trust: The Evolutionary Landscape of Religion’ Arts Disputandi 3
• Animal-Made ‘Art’ Challenges Human Monopoly on Creativity
• Art by animals
• Stoneking et al (2003) Molecular Evolution of Pediculus humanus and the Origin of Clothing. Current Biology 13, 1414 – 1417
• Head lice key to clothing history