At the core of human behavior and activity is our strong inclination, and indeed, our need to be social with one another. All of us, along with other species in the animal kingdom, achieve sociality through some means of communication. Humans, however, have taken communication to a level beyond that of our animal relatives – chimps do not chit-chat, for instance. We have evolved languages which allow us to discuss anything from immediate needs to abstract topics to recounting memories with one another. Though other features such as gestures are shared, language as humans know it is uniquely our own. In reviewing theories about the origin and evolution of language, we can see how it relates closely to our drive to cooperate with one another, and may have evolved first from the gestural capabilities of primates. Despite the gesture-primacy hypothesis not being universally agreed upon, many evolutionary biologists and anthropologists view it as a possible explanation for the source of our language. Most of all, through examining and considering the origins of language, we are able to think more critically about what language says about our species and what it means to be human.
Language is a tool we use everyday to think and communicate with others, so much so that it seems strange to imagine that our distant ancestors may not have had it, at least not like we do. Language, like other human traits, is the result of thousands of years of evolution which selected for traits that allowed the development of language. However unlike other remnants of biological history and evolution, language does not fossilize, which makes determining its emergence in our history as a species basically impossible to pinpoint. There are other clues though, which can direct scientists towards reasonable theories about the origins of language and what caused its emergence. Many scientists use the presence of cave drawings as evidence of language in Homo sapiens, which means that for a long time, language was thought to be about 40,000 years old. This figure is based on the archaeological records which date cave drawings and engravings in Europe to that time (Pagel 2017). Symbolism is a good indication of language development (or at least the potential of language) because an understanding of symbols is crucial for language to exist. We must first understand that different words or sounds represent different objects or ideas to make sense of language. This timeline has some problems though, because it supposes that language began in Europe after Homo sapiens left Africa about 60,000 to 125,000 years ago. Were we to assume that language spread from Europe, or that Homo sapiens evolved the same abilities in different locations? However, as discoveries continue to be made, we can see that the timeline of artwork and symbolism stems back further than was previously thought: we now have found caves in South Africa with painting tools dating back 100,000 years, and engravings dating back 75,000 years (Jabr 2014). Since the history of symbolic behavior in humans extends further back, it follows that the history of language should date back further as well. With the new implications that language did not develop in Europe about 40,000 years ago, we must reconsider our timeline for the emergence of language and what may have caused it.
One cause which has been proposed as a catalyst for speech in humans is a need to negotiate or trade. In a recent anthropological discovery in the Algerian desert, 120,000-year-old seashells which had been made into beads were found, likely having been used in a necklace by early humans. Already, this is a fascinating discovery for what it shows us about the history of symbolism in humans, but it gets more interesting when we consider the location: it was found 120 miles inland from the Mediterranean Sea where the seashells had come from. Though the age of this presumed-necklace far predates agricultural and other more modern factors of society, it is evidence of economic activity in early humans – the shells were likely traded from human to human, probably in exchange for other goods or symbolic items, which allowed them to travel so far from their original home in the Mediterranean (Pagel 2015). This discovery presents us with an even earlier beginning for language in humans, as it could potentially have been about 120,000 years ago. This is significantly older than previous guesses based on cave art, and while the reasoning for speech is consistent (in both cases, evidence of language is assumed due to evidence of symbolism), the discovery of a necklace far inland can present more evidence for a reason behind language evolution. It is possible that language evolved in order for humans to trade and exchange things with one another – after all, how are you going to work out a deal when neither of you can speak? While gestures can be used in simple exchanges, language gives us the freedom to engage in more complex social behavior. It also allows us to talk about other people, which lets us develop reputations (maybe someone cheated you in a trade, and now you want to tell other people this), and work together with others to accomplish a more complicated task by splitting up chores into different parts and organizing the desired final product. These abilities in humans, which we use often in our lives as a cooperative species, are not a part of other animal species which could perhaps explain why they never developed a more sophisticated form of communication – they didn’t have anything to talk about (Pagel 2017). Other theories on the origins of language stress the importance of language in allowing humans to recount stories to one another. This lets us, for instance, describe an event to our peers, perhaps telling them about an instance where we were in danger and what we did to survive. Our peers are then able to learn not through direct experience, but through our telling of the experience they learn what to do or not do in order to survive (Ferretti 2016). Though it is hard to decide with any certainty what caused our language capabilities to evolve the way they have, it is a safe guess that it was largely influenced by (and probably influenced back, in a type of circular relationship) our drive to work together and to learn from one another, as it allows both of these practices to flourish in a way that it does not in other species.
Though we can easily see how beneficial language is for us, it is harder to see how it could have evolved from speechless ancestors and what steps it took to reach this point. Our relatives in the animal kingdom are mute (vocalizations are different from speech), even other apes. One hypothesis which has been proposed to explain how language evolved in humans is the gesture-first or gesture-primacy hypothesis. It was first suggested in the eighteenth century by several thinkers and the idea was reenergized in the late 1960s (Kendon 2017). The hypothesis argues that before spoken language, humans communicated through gestures exclusively. It was from that foundation that spoken language evolved as an adaptation on gestural communication, and so the central component to this hypothesis is that “gesture and speech emerged sequentially” (Aussems 2018). One of the most prominent contemporary proponents of the idea is Michael Corballis, a psychologist from the University of Auckland. He suggests that humans switched from gestures to speech about 50,000 years ago, though he believes language and grammar are older, perhaps even around two million years old emerging first as gestures and grunts. The ability to gesture, and the inclination to do so, would have been driven by the development of bipedalism, as this would leave the hands free for expression (Eakin 2002). It might seem like a stretch to think of humans exclusively using gestures to communicate, but we know from our own experience how useful they can be.
Humans, of course, still make great use of our ability to gesture. Indeed, we often use our gestures in conjunction with spoken language in order to convey our meaning. We point to objects we want others to look at (“That dog is cute”) or we shrug our shoulders to indicate uncertainty. Some gestures can have different meanings depending on context or style of execution, though they are similar in their physical composition: a palm facing up can indicate either “give me that, please” or “what the heck are you doing?”, depending on the accompanying facial expression (eyebrows raised or relaxed vs. eyebrows furrowed) or the manner in which the hand was rotated to face upwards (gently extended vs. flipped upwards suddenly). Even more compelling in uncovering the evolution of our gestural communication is the observation that chimps, too, naturally make use of gestures. We know from experiments that chimps can be taught sign language, but these gestures that they use are entirely untaught by humans, indicating an innateness in primates to gesture. For instance, chimps will offer a part of their body to each other that they want groomed, or mothers will show their offspring the sole of their foot to indicate that she wants them to climb on her back. As with humans, some of their gestures can carry multiple meanings depending on the context, showing the flexible nature of gestures (Gill 2014). Some gestures are even the same between chimps and humans, such as extending a hand with the palm facing up when one needs support or wants to be given something (Pollick & de Waal 2007). Apes’ ability to gesture, but not speak, is a significant defense for the gesture-primacy hypothesis. Since these capabilities are shared between humans and their closest relatives, we can make the educated assumption that our common ancestor did as well. Interestingly enough though, there is at least one gesture which humans have that is not used by apes, and it is an important one. While apes can point at objects they want something done with (such as directing your attention towards something they want you to do, such as open a door, or pointing at food they want), they are incapable of using “declarative pointing (i.e. pointing for the sake of sharing attention, rather than merely directing attention)” (Aussems 2018). We can think of declarative pointing as a type of gesture where the focus of the communication, its meaning, is centered on the receiver, like pointing to something to tell someone “look at that”. Your focus is more on what your partner will think of the object in question than it is on the object itself. Apes do not understand this gesture, they only use pointing in its imperative form, such as saying “open this” or “give me that”.
While this gestural ability is shared, to such an extent that even apes can be taught sign language, the ability to speak is unique to humans. Though chimps (and other animals) vocalize, their vocalizations are not the same as our symbolic speech. Instead, their vocalizations have more in common with say our instinctual cries after being hurt – they don’t mean anything other than “I’m hurt”, and often we do not really intend to communicate a message with those reactions, it is an automatic response (Gill 2014). In apes, their equivalent of the Broca’s area of their brain (an area identified in the human brain relating to language abilities) is “activated during both the production and the perception of gestures but not vocalizations” (Pollick & de Waal 2007). This fact leads many to believe that, since this area of the brain is active for humans when communicating and for apes when gesturing, language must stem from these gestures rather than the vocalizations which have no interaction with the Broca’s area.
The gesture-primacy hypothesis is a compelling and convincing explanation for the potential source and evolution of language in humans. However, not everyone agrees with the concept, each with their own reasons depending on their own background of study or contrasting theory which they hold about the origins of speech and language. Linguists, for instance, do not agree with Corballis’ claim that language and grammar preceded speech, saying that he “doesn’t appreciate the sophistication of grammatical organization” (Eakin 2002). Others have pointed out that while the concept astutely directs our attention to the limited control that non-human species, such as other primates, have over their larynx (creating an impediment to potential speech), it doesn’t tell us why we developed such an exclusive ability (Kendon 2016). More theories still propose that language could come from the grooming habits of apes, the movements of the mouth when it is chewing, or from “rapid mental reflexes” (Eakin 2002). A question remains as well: if we were so good at communicating with our hands and had developed a language from gestures, why did we ever switch to speech? Michael Corballis believes that the shift from gestures to speech coincides with the “explosion of technology, cave art, textiles, and even musical instruments” that occurred about 50,000 years ago (with newer discoveries of art which predate this time though, it is likely the figure is greater than 50,000). He connects the shift from gestures with an increase in art because he argues that speech freed up our hands to let us make things. He also has posed the thought that Homo sapiens did not start speaking because of a sudden genetic or neurological mutation, but simply because it was a “cultural invention” – it seemed like a good idea to them (Eakin 2002).
The origins of language will never be known with one-hundred percent certainty, but that doesn’t mean we can’t reach some conclusions or propose plausible theories about its beginnings and its evolution. The gesture-first hypothesis presents us with a credible explanation for our language origins by examining how similar our gestures and speech are to the gestures of our closest relatives. Why then, did chimps not follow suit and begin to speak? This seems to tell us something important about what it means to be human. Many of the possible reasons proposed for why we developed communication the way we did is that we had a need to talk to each other – a need for a better way to cooperate, teach, learn, and develop our culture in more complex ways. The gesture that chimps do not understand, the declarative point, is crucial for how humans live. It puts the focus not on the object, but on what we want to communicate about the object and how we expect another person to feel about it. This kind of pointing needs more explanation with it than just a gesture if we want to explain to others how we feel or think about the object we are pointing to. Perhaps it is from this gesture, this ability of theory of mind, that our language takes its strongest roots. Chimps don’t need language the way we do because they don’t need to talk about other things or other chimps, but humans, with our highly social communities constructed around building relationships and reputations, need a way to talk about others. Maybe an important part of what it means to be human, is that we need to gossip, we need to show, we need to make deals, and we need to explain.
Literature Cited:
Aussems, Suzanne, 2018. What Hand Gestures Tell Us About the Evolution of Language. iCog.
Eakin, Emily, 2002. Before the Word, Perhaps the Wink?; Some Language Experts Think Humans Spoke First with Gestures. The New York Times.
Ferretti, Francesco, 2016. The Social Brain Is Not Enough: On the Importance of the Ecological Brain for the Origin of Language. Front. Psychol.
Gill, Victoria, 2014. Chimpanzee Language: Communication Gestures Translated. BBC.
Kendon, Adam, 2017. Reflections on the “Gesture-First” Hypothesis of Language Origins. Psychon Bull Rev. 24(1): 163-170.
Jabr, Ferris, 2014. Hunting for the Origins of Symbolic Thought. The New York Times.
Pagel, Mark, 2017. Q&A: What is Human Language, When Did It Evolve and Why Should We Care?. BMC Biol. 15: 64.
Pagel, Mark, 2015. Why We Speak. The Atlantic.
Pollick, Amy & de Waal, Francis, 2007. Ape Gestures and Language Evolution. PNAS 104(19) 8184-8189.
Olivia Michael Tarman 