Soon after the appearance of Homo sapiens, other examples of social learning and culture began to show up in the fossil record. Samples of haematite, a red iron oxide that can be used as pigment for body adornment, have been found in Zambian sites dating to around 160,000 years ago. Ceremonial burials including a man clutching the jawbone of a wild boar have been dated to around 115,000 years. Other graves of the same period contained beads. Why go to this effort unless there was some symbolic meaning for the objects?
As they rapidly spread geographically across the planet, Homo sapiens must have been equipped with a brain capable of much more culture than ever seen before. Based on a statistical analysis of the global data set of mtDNA sequences, it is believed that there was an increase in the Homo sapiens population around 100,000 years ago that would have produced a demographic that was ripe for enabling culture to flourish through the exchange of ideas and migrations of individuals.35
From around 100,000 to 45,000 years ago, there had been sporadic examples of cultural practices such as ceremonial burials and symbolic behaviour like art and body decoration. However, in Europe around 45,000 years ago, Homo sapiens became anatomically modern humans engaging in all the trappings of primitive civilization. They were as close to us today as we can find in terms of their bodies. They also behaved much more like us than any other ancestor. Around this time there was a cultural explosion as evidenced by the advances in tool technology, elaborate jewellery, symbolic sculptures, cave paintings, musical instruments, talismans and the spread of religious ceremonies and burials.36 Each of these activities was undertaken for a purpose that required a level of social interaction far in excess of anything seen before or remotely present in the animal kingdom. Humans had clearly begun to trade, as many of the raw materials for the artefacts had been transported great distances. In other words, we were already becoming vain. Art and jewellery are primarily made to be seen and admired by others. Making jewellery and creating art took considerable time and effort and would only have been undertaken and appreciated for the social value such activities conveyed. Burials and religious ceremony reflect an awareness of death and thoughts about the afterlife and creators. It may be true that some primates show the behavioural signs of mourning their dead, but modern humans are the only species that engage in death rituals.
The psychologist Nick Humphrey has suggested that it would be more appropriate to call our speciesHomo psychologicus (psychological man), given the ability of Homo sapiens to read minds – not in any supernatural psychic way, but simply by imagining what someone else is thinking and predicting what they may do next.37 You need to be able to read others if you are a member of a species that has evolved to co-exist and, more importantly, cooperate. You also need these skills if you are producing helpless infants who need childcare and shared rearing. In order to make sure that you have enough resources for yourself and any offspring, you must be able to understand and anticipate the intentions and goals of other members of the group.
This is particularly true of primates who engage in deception and coalition formation, sometimes called ‘Machiavellian intelligence’ after the Italian Renaissance scholar who wrote about how to govern through cunning and strategy.38 This ability requires a set of social skills known as ‘theory of mind’ in the psychological literature and represents a powerful component of social intelligence.39 When you have a theory of mind, you are able to mentally put yourself in another’s shoes to see things from their perspective. This enables you to keep track of others, to second-guess their intentions, to outwit them and to exchange ideas. As we will read in later chapters on child development, theory of mind has a protracted progress and for some unfortunate individuals remains impaired, which presents a considerable hurdle in communicating with others.
The chattering brain
One uniquely human social skill that we regularly use for problem solving is language. Although we sometimes talk to ourselves, the primary purpose of language is to communicate with others. We learn to speak by listening to others, and if we were raised in an environment where we heard no language, then all the evidence indicates that we could not learn to speak normally at a later age, no matter how much training and effort we put in. There is something in our biology that dictates that we must be exposed to language at a critically early age to acquire it.40 Even learning a second language becomes increasingly harder as we age, indicating that there is a biological window of opportunity for language acquisition.
Just about every facet of human activity involves language, whether it is work, rest or play. No other animal on the planet communicates like we do. They may have squawks, barks, grunts, squeals, snorts, screams, cries, hoots and all manner of noises, but the information they are communicating is extremely limited and rigid. Despite what Walt Disney and other animators would like us to believe, animal communications are nothing more than elaborate signalling systems to convey one of four simple messages:
‘Watch out, there’s trouble about.’
‘Back off, man, I mean business.’
‘Come and get it, there’s food over here.’
Or more often than not,
‘Come and get it, ladies, I’m over here.’
Animal communication is primarily for the four Fs of fleeing, fighting, feeding and fornicating – basic drives that keep us alive long enough to pass on our genes by reproduction. Humans also spend a considerable amount of time communicating on these very topics but when we communicate, there is nothing we better like to do than talk about others. An analysis of typical conversations in a shopping mall revealed that two thirds of the content was related to some social activity – who’s doing what with whom.41 Human communication is not restricted to biological drives that are necessary for survival and reproduction. We can talk about the weather, politics, religion and even science. We can pass on opinions, instructions and all manner of other high-level, complex information, though in all likelihood our initial communications when language first appeared were probably directed to the same four Fs that were necessary for survival. After all, human communication is complicated and difficult to execute and therefore must have evolved for a good purpose.42
Why can’t we talk with the animals? First, we are the only primates with the motor machinery that enables us to vocalize the controlled sounds that form the building blocks of speech.43 Most notably, unlike other primates, we have a descended larynx. The larynx or ‘voice box’ serves a number of roles. As we exhale, the air passes by the vocal cords that vibrate to create sound in the same way that blowing across a blade of grass produces a quacking sound. Changing the shape of the mouth, tongue and lips as well as controlling our breathing can further modify these sound segments to produce the differing vocalizations. The other main role of the larynx is to close up in order to protect us from inhaling food, but it does not begin to descend in the human until around three months of age, which explains why babies can swallow and breathe at the same time when they are breastfeeding.