The selective advantage of consicousness in humans? Understanding each other.

Sam Harris recently interviewed his wife, Annaka, on his "Making Sense"podcast to discuss her new book on consciousness. One interesting exchange concerned the idea of "panpsychism," the view that consciousness is somehow inherent to matter itself. Both parties expressed a certain sympathy to the panpsychic view in light of a perceived inability to show a selective advantage to consciousness that would cause natural selection to produce and develop it. I'd like to argue here that the Harrises have missed a plausible and profound Darwinian advantage to consciousness, as well as the intuitions of free will, self, and agency; namely, the ability to predict what other human beings will do.

Humans (Homo sapiens and our hominid ancestors) have been part of relatively large and sophisticated social groups for millions of years. These groups have been both complex and remarkably effective; the culture of tool use alone, passed on without the aid of genetics from generation to generation for at least 2.6 million years, shows how important social groups have been for humans. Of course, as soon as one is part of a social group, there is a decided advantage in predicting how other members of that group will behave. It's easy to imagine how predicting the reaction of another human to one's aggression, consoling, or flirting would boost an individual up the social hierarchy and contribute to the number and fitness of that individual's offspring, thus enhancing that person's inclusive fitness. So traits that enhance the ability to predict the behavior of other humans would almost certainly confer a selective advantage.

The way we, as conscious people, regard other humans is shot through with the intuitions discussed by the Harrises - we see others as individual agents that make choices based on internal drives and desires. While those intuitions may not match up with our 20th century understanding of physics and neuroscience, they are nonetheless really useful models of other humans and their behavior. We may be far from perfect from predicting the reactions of others, but modeling them as agents still makes sophisticated and powerful predictions of what they will do (perhaps this ability reaches its zenith in the modern kindergarten teacher near the end of the school year). Those intuitions are also quite efficient; modern neuroscience has shown us just how much complexity underlies our simplistic ideas of how others behave, and therefore just how much computational effort we avoid by using the simpler model of others as decision-making agents. Further, the conscious post-hoc narratives we construct about others generally improve our predictions of what others will do (hence the difference between a beginning-of-year kindergarten teacher and the same teacher at the end of the year). So while our intuitions about others may not be strictly correct, they are still a vast improvement over a  reaction of merely fear or disgust, and we should not be surprised at the widespread adoption of those intuitions across humanity.

Given the practical utility of seeing others as agents with free will, it is not that surprising we might turn the model upon ourselves. Understanding our own behavior as agents that make choices based on drives or desires can help us better interact with our fellow humans. Telling ourselves stories about  why we make the choices we make - and what goals we believe motivate us - both helps us control our own reactions to others and plan our social strategies in much more nuanced ways that simple emotion can. Having the patience to wait for an opportune moment to challenge a rival or seek out an ally relies on the kind of ongoing narrative that consciousness provides. Even if consciousness is a post-hoc story we tell ourselves (as tantalizing results from the past few decades suggest) the potential to refine our future actions to better serve our interests is immense.

In case the reader is not yet convinced of the practical value of a conscious perception of other humans, a somewhat recent review of the selective advantage of various steps on the way to human consciousness (including the social advantages) by Michael Gratziano may be helpful.

One might object along the lines of "zombie" thought experiments that all this modeling of agency and narrative could be unconscious and still effective; why would it be necessary for the "lights" of awareness to be on to make good predictions about what we and others would do in social situations? We must concede that we really don't know what that possibility looks like; perhaps some future unconscious social genius AI will show us. Or perhaps a mental model sophisticated enough to effectively model our social interactions through a narrative of independent agents just equates to consciousness. Or maybe once that mental model is constructed, generating awareness is a low-cost adjustment that permits even more sophisticated predictions based on conscious reflection in memory.  Judging from our position as conscious beings, it's just hard to evaluate the other possibilities.

It is also important to point out that our intuitions about consciousness in other species generally correlates with social sophistication (the blog does have "empiricist" in the name). Whales and dolphins; dogs; other primates; birds like crows or parrots; even prairie dogs; all these social species are ones we intuitively suspect may have the "lights" of consciousness on, given their apparent ability to perceive and react to the emotional states of their peers and even us. Even the counterexample of social insects is instructive; we don't generally ascribe consciousness to, say, ants or honeybees, because the individuals in those societies behave in quite programmed and stereotypical ways to each other (as well as being bound by inclusive fitness). Further, the behavior of hives or colonies of social insects is not particularly sophisticated with regards to other hives or colonies; the typical interaction between ant colonies, for example, is ruthless (perhaps mindless) all-out conflict.

So far from being selectively neutral, the intuitive models contained in our conscious awareness are profoundly useful in navigating the complexity of even hunter-gatherer human societies. Indeed, they have likely been useful for millions of years, and perhaps across many different groups of social animals. While we do not know whether our particular self-aware version of these models is the only way to gain that predictive utility, it is not hard to see the adaptive value of a conscious representation of the world for a social animal. There is no need to conjure a panpsychic conscious property of matter itself, just as there was ultimately no need to define a "vital" force animating matter into living things. We have sufficient reason to predict that consciousness would be selected for as animals began living together in groups that were large enough for its mental models to matter.

The Agency problem

I recently heard an interesting podcast on "memes" and the extent of their similarity to genes. One of the hosts (and many online commentators) had trouble with the idea that memes (units of information transmitted among humans) could replicate themselves - after all, a song or phrase doesn't copy itself, does it? This was contrasted with genes, which we were assured could self-replicate, and thus the meme idea was dismissed. We can choose whether or not to pass along a pithy phrase, so it doesn't have the status that a gene does.

Of course, to anyone who understands genetics, the idea that a gene "self-replicates" is pretty silly. Aside from a few special sequences of RNA (and damn if those aren't interesting) DNA is just a molecular encoding of information - not fundamentally that different from a long string of text. Genes are particular stretches of DNA that code for useful proteins, but they are still just information. It takes a bunch of molecular machinery inside a cell to copy that information (or, for that matter, to convert it in to a protein). While it's true that the individual enzymes that copy, transcribe, and translate the information are produced from genetic information, it takes a collection of genes working in concert to duplicate any of the individual genes. For the gene to become more common in the world, it has to be in an organism that survives and reproduces. Genes replicate, proliferate, and disappear in cells in organisms (even if those organisms are unicellular), and genes can't "do" anything on their own.

So why does everybody just assume genes are doing their thing replicating and proliferating? Well, the fact that Richard Dawkins's groundbreaking book was called "The Selfish Gene" may have something to do with it. Dawkins pointed out that from the point of view of a gene, an organism is a "survival machine." Genes don't really "care" about individual organisms beyond their ability to promulgate genes. To bolster this view, Dawkins (correctly) pointed out that individual organisms (and even species) are incredibly short-lived compared to genes; hemoglobin genes, for example, are something like 500 million years old, and the genes for enzymes like DNA polymerase are presumably as old as DNA-based life itself - which is the only kind we know (and yes, RNA viruses are still DNA-based; they require the use of plenty of proteins from their hosts' DNA to reproduce). Most folks seem to accept some sort of independent drive for genes since Dawkins published the book - hence the idea that they are "self-replicating" - and the way Dawkins pointed out that evolution was not just about the survival and reproduction of organisms was a big step forward in understanding. Nonetheless, the idea that emerged ("it's all about the genes") is just plain mistaken.

The problem here is that we humans are used to the idea of agency. That is, changes come from agents which are capable of action in the world. In human political and social systems, agency is a basic assumption; if something happens, somebody must have done it. It's a great concept for explaining a market or a legislature. In understanding an evolutionary process, however, agency is basically useless, because changes occur at so many levels (gene, organism, population) at the same time that one just can't ascribe evolution to a single agent. Genes don't evolve on their own; neither do organisms. Populations evolve (change genetically over time) only to the degree that individuals in the populations are more or less successful at surviving and reproducing, but the change is at a genetic level (usually described as a change in gene frequencies). So who is the agent?

Really thinking deeply about this is hard when you're raised on agency; hell, even evolutionary biologists use Darwin's term "natural selection," as if some agent ("Nature") was carefully deciding who deserves to survive. That, of course, is not just nonsense, but unnecessary; organisms just survive and reproduce, passing on genes that determine part of the likelihood of survival of those organisms. In that situation, there is no agent that has to "select"; instead, better-surviving libraries of genes emerge in the surviving organisms, period. Evolution is literally the most natural thing to happen to reproducing organisms with some sort of genetic system, no agent required.

Back to memes. We have information (words, phrases, ideas, music) that sits around on its own, but tends to get passed around when you have people talking to each other. We (people) use information, share it, find it helpful, tell our kids. Nobody has to go out and force us all to put "ROFL" in our social media posts, but it works, and it spreads. That's a meme, and it deserves the same sort of respect as a concept in social informatics that a gene does in biochemistry. OK, I made up the phrase "social informatics," but you get the point. Genes and memes spread, or they don't; one is biological evolution, the other social evolution, but in any case, there's no point to trying to find the Agent of Evolution behind it all. In a situation where genes or memes can be copied, it just happens.