Explanations, explorations and celebrations of human consciousness have absorbed cultures and fascinated thinkers since the beginning of history. But many think they appear to have yielded few concrete answers about consciousness itself. In the 21st century, under scrutiny of scientific enquiry, the study of consciousness still seems to generate more questions than clear-cut conclusions.
Yet at the same time, more than 100,000 papers from the vibrantly interdisciplinary field of consciousness studies stand testament to what we have learnt about this most intimate yet most mysterious aspect of our very existence.
Ponder the anonymous skyline of any one of our planet’s megacities and it seems hard to refute the notion that we are more successful than - more advanced than - or even somehow unique in relation to our animal cousins. If prompted, most people would eventually appeal to something about the human mind or the way in which we think that makes us the species that we are. Indeed, according to our Latin nomenclature at least (Homo sapiens), we are the “wise” member of our local branch of the wider hominid family tree.
This two-part exploration into consciousness draws on neuroscience, behavioural science, evolutionary biology, philosophy and futurology to ask three questions. This first essay will ask how and why consciousness came about. Part two will build on this to ask what consciousness is as well as what it might mean for us as a species. The searches for answers to these questions are in no way complete, but the knowledge we are accumulating is beginning to reveal fascinating insights into who we are: insights that suggest that we may not be that special, after all.
The Cartesian theatre
The multitude of ways in which we might describe a person as conscious indicates the ambiguity of the term in English. In one of the most basic senses, consciousness can simply be that which is awake, or animated. An observer might declare an adult roused from the effects of a serious fall to be “conscious” if their eyes were open and tracking movement.
Yet at first glance, most animate beings seem to miss out on a sense of consciousness that feels very important to us. That is the quality or experience of being aware of something or other, which is quite a particular state of being. The person recovering from their fall may not be able to provide meaningful answers to basic questions about themselves; they might not be “conscious of” where they are or how they came to be there.
For hundreds of years, the lack of an identifiable physical seat of consciousness resulted in a lot of foot-dragging.
Thinking about consciousness as “a state of being conscious of something” avoids a lot of sticky questions. For example, is consciousness that sense of being alive when the clouds roll back on a summer day and the sun douses the land? Or is it the taste of coffee in the morning, or the memory of a distant birthday? Might we find it in the silence of that knowing look shared between someone who’s just told a lie and the listener who recognises their attempt at deception? Being conscious of an experience, of a sensation, of a memory and of another mind all seem to be very different things. It turns out that all of these things share one property: the curious fact that they are all experienced by a unified observer looking out from inside.
Many of us are aware of how fragile the constant, internal narrative underlining our lives actually is. Any lapse in the normally steady supply of essentials (oxygen, glucose, blood) to our brain can cause a range of typically unpleasant but usually temporary changes in how we experience the world and, in some cases, whether “I” am even able to experience anything at all.
We also know that removing or damaging specific parts of our brains can result in a thousand mini-eclipses and malfunctions of the various components that make up human consciousness. These include a loss of the ability to speak, a failure to acquire conscious memories, dramatic changes in character and even “forgetting to breathe” when asleep. Sleep itself indicates how states of awareness are linked to our brain’s electrical activity and we now understand how some “maladies of consciousness” - such as epilepsy or certain types of hallucinatory experience - manifest as electrical glitches.
All of this serves to underline that my experience of being me appears to be a thoroughly physical affair: the stuff of neuronal firing, specialised bits of brain and healthy supplies of fuel. Yet at the same time, consciousness just doesn’t seem to be physical; it can’t be observed or even described very well. For hundreds of years, this lack of an identifiable physical seat of consciousness resulted in a lot of foot-dragging.
Even now, some philosophers and scientists remain in thrall to the intellectual-equivalent of abject surrender: the idea, à la Descartes, that since we can’t seem to find consciousness (read “the soul”) anywhere in the body, it simply isn’t material and must exist in another realm altogether. The association of words like “soul” with consciousness had, until relatively recently, resulted in its systematic dismissal as a subject of study within the fields of cognitive science and neuroscience. But there has also been a lot of “guerrilla” consciousness research - studies that, whether intentionally or not, have revealed useful information about the form, nature and history of that special experience of being a “me”.
A science of correlations
Generally speaking, we know quite a lot about the nervous system: the sophisticated electrochemical signalling network of cells (neurons) that makes up our brain, spinal cord and the nerves branching throughout our body. Of course, we haven’t just studied the human nervous system. We know that the neural signalling systems of our animal cousins use the same electrochemical messengers (known as neurotransmitters) and share the same basic properties, such as “plasticity”: the adaptive rewiring of neural networks in response to change, injury and disease.
Studying nervous systems has given us several fascinating insights into consciousness; namely that it essentially exists, to varying degrees of complexity, in most creatures. At the lower end, for instance, sea snails demonstrate how organisms with more than 4m fewer neurons than ourselves exhibit basic forms of learning.
Acknowledging the idea of some kind of gradient of consciousness was one of the big breakthroughs in our understanding of mind. We were at somewhat of a disadvantage in realising this, because our own individual experience of the world suggests that consciousness is more akin to some kind of on/off switch. Something is either aware or it is not aware - you either have it or you don’t. Such an intuitive sense and high threshold for what we consider to be conscious has had important implications throughout history. Conceiving of others - both human and animal - as “soulless” automatons has served as the philosophical foundation for a whole range of ethically problematic activities from factory farming to colonialism.
We have to think of consciousness as something a bit analogous to a computer: an information-processing system.
Understanding that consciousness exists at different levels is challenging because of a certain bias we all possess: that highly-developed concept of self – our self-awareness – that thinks of everything “below” it as fundamentally alien. But the development of our own minds in early childhood can provide some useful analogies into these different stages – or degrees of complexity – of consciousness.
By the second trimester of pregnancy, most of our brain’s billions of neurons have already developed and we can see and hear (our sense of touch exists as early as week five). Sometime in the third trimester, rapid-eye movement (REM) sleep kicks off. REM sleep, the only period of sleep where neuronal activity resembles that of our waking lives, is strongly associated with dreaming and is something we share with most mammals and birds. Some developmental psychologists believe that our experiences in the womb - as well as those during and just after birth - can create permanent imprints on us and even be recalled in some detail in later life.
But the question, to paraphrase one famous philosopher of mind, remains; what is it like to be a baby?
The first big milestone for the human mind occurs around 15 to 18 months, which is roughly the time that we develop a form of self-recognition. This has famously been tested by observing whether a mirror can be used to identify marks on one’s own body that would otherwise be invisible. Human babies of this age, chimpanzees, orcas and even the Eurasian magpie all pass the so-called “mirror test”.
Of course, the mirror test doesn’t tell us much about the mental life of an 18-month old child (or a bottlenose dolphin), but it does tell us that the organism can be thought of as “self-sensing:; that is, it has the ability to pick itself out as a subject from among the various objects that make up its reality. It does not seem to be a coincidence that our mastering of first-person pronouns also occurs around about 18 months. Nor, perhaps, does the fact that most of the adult mammals that are able to pass the mirror test also demonstrate the use of languages.
If the early months and years of our childhood see a gradual development of personhood - what we will come to eventually recognise as an “adult human consciousness” - what is driving it? We know that the central nervous system itself has already been around since the third trimester of pregnancy. To understand what is happening, we have to think of consciousness as something a bit analogous to a computer: an information-processing system.
As more and more synaptic connections form and the overall complexity of the neural network increases, so does the processing power of the system. So cognitive development could be thought of as a series of software upgrades. But then don’t the varying degrees of complexity in consciousness also need to take account of differences in hardware?
The idea that the biological development of our brain during our early lifetime (part of our ontogeny) tracks our evolutionary path (our phylogeny) is now widely discredited. An embryonic human nervous system may look a bit like a fish’s but… it isn’t it. The once popular model of a smoothly progressing “reptilian brain” (cerebellum and brain stem) sheathed within a “paleomammalian brain” (limbic system) covered by a “neomammalian brain” (cerebral neocortex) has proven too simplistic.
When it comes to consciousness, a world in which birds possess brain structures that serve the same function as our neocortex - enabling, for example, species such as the New Caledonian crow to manufacture and use tools - forces us to acknowledge the sheer majestic diversity in the phrase “varying degrees of complexity of consciousness”.
A theory of mind
There is a difference between being able to pick yourself out as a subject among other objects and being aware of yourself as a subject that experiences objects. To use a mirror to identify yourself is different to recognising that, as you look into a mirror, you are experiencing a physical representation of your self. The latter requires a belief: that you have a mind. The upshot of this is that three-year-olds aren’t quite aware of where their beliefs come from; they can’t accurately remember whether they have been told about or actually shown an object upon being asked about how they came to know about it.
A five-year-old, however, does remember and they can also do something else a three-year-old can’t: deceive. To be able to lie effectively, we have to have an idea of another being that experiences the world just like us. That development heralds not just a software upgrade but a brand new operating system.
The field of epigenetics has dismantled the idea that we’re stuck with the DNA we are born with. DNA, of course, is the genetic language through which traits are inherited across generations. But epigenetics is showing how our DNA is continuously changing based on our environment, experiences and emotions and redefining how we understand evolution.
So what about that operating system, a “theory of mind”, which enables the five-year-old to lie effectively? Our social interactions all rely on a theory of mind, the ability to recognise others as beings like ourselves. Human social interaction has been strongly shaped by the evolution of our consciousness, and vice versa. But the implications of another idea suggest that the richness of human consciousness may be related to a new form of evolution as we understand it.
The richness of human consciousness may be related to a new form of evolution as we understand it.
When many people think of memes, they think of images involving cats, or caricatures and amusing subtitles. As internet memes demonstrate, a meme is simply “an idea, behaviour or style that spreads from person to person within a culture”. However, the evolutionary model of memetics, pioneered by evolutionary biologist Richard Dawkins, basically suggests that memes operate like genes; they are units of information that have an independent existence (think books or folk tales or laws); that are self-replicating and that undergo selective evolution in response to the environments in which they exist.
The essential argument, to give a stripped-down example, is that a grandmother being able to describe the colour, shape and flowering season of a poisonous berry to a foraging granddaughter is a means of transmitting information that can affect her granddaughter’s behaviour in an evolutionarily advantageous way. All of this involves components of human consciousness: beliefs, language, a theory of mind. But the implications of memetics for human consciousness, go far beyond this.
Firstly, just like genetic evolution comes up with the same things, like visual organs, through entirely independent pathways, so does memetic evolution. Social learning across cultures can create similar “units of information” that affect collective behaviour; think of the “Golden Rule” (“Do unto others…”) that’s popped up everywhere from Ancient Babylonian laws to Hellenic philosophers to Taoist thinkers. But the really interesting thing is the speed at which memes are created; they can change - for better or worse - each time they are passed from person to person. In other words, the mutation rate in memetic evolution is extremely high in comparison to genetic evolution.
This, as philosopher of mind Daniel Dennett puts it, means that we “can rise above the imperatives of our genes - thanks to the lifting cranes of our memes.” Now just take a moment to think about how fast a broadband connection transmits information compared to a telegraph network, or an early printing press.
So what about consciousness? Well if you think of the collection of an individual’s ideas, beliefs and behaviours as undergoing a process of memetic as well as genetic evolution then that old phrase “varying degrees of complexity of consciousness” becomes, well… more complex. We aren’t just talking anymore about the acutely different consciousnesses of a sea-snail, a pig, a bonobo, a human baby and you and me. We have to acknowledge that the complexity, form and limits to the conscious experience of reality of a modern human adult versus that of a Spanish conquistador, a Zhou dynasty peasant or a Roman statesman are all fundamentally different.
So the gradient of consciousness doesn’t stop at species. It’s an evolving continuum, branching out like a tree across species but also spanning throughout recorded human history and reaching out to the consciousnesses of our ancestors, like the language-using Homo heidelbergensis of 600,000 years ago; right back to the point, some seven million years ago, when we diverged from our cousins, the apes.
It is this development and gradual increase in the sophistication of consciousness - from self-sensing to self-recognising to self-awareness and all that’s in between - that is a critical part of understanding why our species has seemingly achieved such evolutionary success. And, in comparison to deep time, it is the seemingly exponential speed at which memetic evolution unfolds that is one of the key components of thinking about the future of not just our consciousness, but of the human species itself.
So what actually is consciousness? Is it physical, or some vague -ism in between? And what does it mean for us, as a species, in this universe?
As we’ve seen, by exploring how the brain and consciousness develop as an information-processing system throughout our lifetimes, we’ve encountered two important insights. Firstly, that consciousness exists to differing degrees among most forms of life on Earth. And secondly, that one of the hard-to-define thresholds on this gradient heralds an era whereby a species might dramatically accelerate the development of its consciousness through using concepts and beliefs (memes) as an additional vessel, along with genes, through which evolution unfolds.
My second and final essay, Consciousness 2: On meanings and futures, builds on all of this to address two things. It will tackle some of the philosophical questions about what consciousness actually is and also explore a few of the implications of our particular brand of consciousness and what they might mean in the grand scheme of our place in the universe.
I will present two arguments. Firstly, that our emerging understanding of what consciousness could, and perhaps should, shatter our conception of ourselves as “special”. The second will suggest that we are failing to recognise the important possibility that, one way or another, our “special” experience of being self-aware might be leading us sleepwalking into extinction.
Daniel Murphy is a researcher with an Asia-Pacific focus primarily interested in human mobility and labour issues in commodity supply chains using political economy and systems approaches. Oh, and consciousness. He tweets at @DanielMurphy0