The mind as a courtship ornament

Right now I'm reading The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature by Geoffrey Miller. The author's thesis is that the human mind evolved for the purpose of courtship. The reason we're able to tell jokes, build monuments, compose sonatas, and follow fashion is the same reason peacocks are able to grow such magnificent tails and beetles have such elaborate markings on their bodies.

Central to the author's argument is his distinction between natural selection and sexual selection. Miller uses natural selection to denote "changes in the gene pool of a species due to differences in the ability of individuals to survive and reproduce." By contrast, sexual selection is "evolutionary change due to heritable differences in the ability to attract sexual partners, repel sexual rivals, or do anything else that promotes reproduction." While recognizing this is not the way biologists typically use these terms, he points out that Darwin himself used the terms this way, and that conflating them led to errors in the first 150 years of evolutionary science which we are only beginning to dig our way out of.

According to Miller, evolutionary psychologists have made the mistake of viewing the mind only in terms of what it contributes to our survival, treating it like a "swiss army knife" (Pinker) that evolved to deal with a harsh environment. There are several problems with this view, according to the author, amongst them: If large brains and complex minds are so essential to survival, then why did they arise so late in evolution? Why do so few species have them? Claws, wings, and eyes have evolved separately in many species; yet we're the only species that tells jokes and writes sonatas. Why is there such a long lag between the brain's expansion and its survival payoffs? We seem to have reaped the vast majority of them in only the last few thousand years.

We spend a gross number of our calories every day supporting a giant organ with no immediate survival benefits. Yet while natural selection is rather poor at explaining all the brain's abilities, sexual selection is very good at it. Like the peacock's tail, it's a large, wasteful display. And like the courting behaviors of many animals, our abilities to converse, socialize, get along, treat people with respect, charm, flatter, and know what is appropriate are all good fitness indicators. Sure, we reproduce with people who are nasty and uncouth, and we spread those genes through the population, but it's not like we go out looking to do that. People with normally functioning brains are generally socialized, and we prefer that.

I don't know if I'm wholly convinced by his argument. I read a few reviews of the book, and they repeated some concerns I have with the project. What's gotten my attention in this book is that he proposes a new way to understand evolution generally over the last half billion years.

If many innovations originate through sexual selection, we would expect most micro-innovations that distinguish one species from another to be sexual ornaments. This contradicts some traditional views of how species split apart, but, surprisingly, this is pretty much what biologists see. The vast majority of species-defining innovations seem inconsequential for survival. Francis Bacon, father of the scientific method, disparaged the seemingly pointless variety of plants and animals, calling them "the mere Sport of Nature." Darwin was equally perplexed, often wondering why there was so much variety but so little real novelty. If innovations spread through populations because of their survival benefits, why do so few innovations show the survival improvements associated with major innovations and adaptive radiation?

We tend to think of evolution as a series of mechanical "pushes" without any "pulls". Mutations arise each generation because of random copying errors at the molecular level. Most mutations are deleterious to the organism, and if they were allowed to proliferate, species would quickly go extinct. But the environment imposes pressure on organisms. Certain mutations make the organism unable to survive in the environment long enough to reproduce and pass its genes on. Rarely, a mutation will confer some extra survival benefit on an individual, and that new gene may proliferate through the population, creating many individuals who have this gene. When individuals with the new genes are no longer able to reproduce with individuals without them or with different genes, there is a new species.

In place of this purely mechanical view of the history of life where mutations arise by accident, and the environment either favors or rejects them, Miller is suggesting a story in which choice plays a much larger role in the direction of evolution. Novelties arise and survive in species, not for the purposes of survival, but for the purposes of attracting mates.

Sexually selected novelties of this sort could be called "courtship innovations." Most will be nothing more than a slightly novel design for a penis, a minor variation in mating coloration, or a different style of courtship dance. But from these humble origins, a small proportion of courtship innovations and their side-effects may turn out to have some survival benefits in addition to their courtship benefits. They may then become favored by natural as well as sexual selection. Of these survival adaptations, a small proportion may prove significant enough to allow a species to invade many new environmental niches. They produce adaptive radiations, proving themselves over time as major innovations. The ecological success of major innovations may hide the fact that many of them originated as courtship innovations.

And then he goes on to tell a story in which wings may have originated, not for the purposes of flying and evading predators, but as sexual displays for dinosaurs. There is a similar story to tell about the evolution of large brains in hominids.

If this is true, it explains just as much as natural selection does and more. It explains why there is so much novelty in nature, and it explains why this novelty first arises with the invention of sexual difference. For the majority of its time on Earth, life has consisted in single-celled organisms no larger than a millimeter across. We're still outnumbered by them. There are at least 10 times as many bacterial cells in your body as human cells.

But there probably aren't as many species of bacteria as there are of more complex creatures. Considering how few in number more complex creatures are relative to single-celled organisms, it's amazing how much difference we exhibit. Most of the macro-level differences are color of fins, facial hair, feathers, or other sexual displays that confer no obvious survival benefit. Indeed, there appears to be a sublime abundance of types of life above and beyond what mere necessity would predict but which we would expect if sexual selection takes the lead over from natural selection.

The "pushes" (natural selection) may have the final say, but only if the "pull" (sexual choice) egregiously contradicts the demands of the environment. Between what life whimsically craves and what the environment unconsciously rebukes, there appears to be a lot of wiggle room.

And of course sexual selection involves choice. It's minimal with a pair of earthworms, but it becomes quite complex when you get up to insects. Is there something that it's like for a female beetle to be excited by the colorful display of a male beetle? We'll never know, though that display, which is wasteful and dangerous because it attracts predators, plays a function in beetle courtship.

As one moves to more complex forms of life, the choices are also more complex. It's doubtful a male bird of paradise is just exciting a female. I don't think it's excessively anthropomorphic to say he's trying to impress her. There may be no difference between those two things from a purely physical point of view. It's all just neurons firing. But the courtship ritual is more complex and has greater texture of meaning, and the female has to take more things into consideration, so her act of choosing is more complex.

I wrote earlier about Teilhard's law of complexity/consciousness, according to which "mind" is present in all matter, but it increases proportional to the complexity of the arrangement of matter. I think what Miller is arguing might add some depth to that idea. The invention of sexual difference allows choice (a proto-subjective state) to arise for the first time, and it allows for the evolution of greater complexity (and hence more complex and varied distinctions between "inside" and "outside"). That's why life really takes off half a billion years ago.

Did this revolution—call it the original Sexual Revolution—have to take place? Would any planet with life on it have to eventually invent sexual difference? I don't know. However, it's intriguing to think that, given the Sexual Revolution, complex minds had eventually to evolve.

I have to think about this and develop it more, but I'll end with this quote from Miller:

We can see that, once sexually reproducing animals evolved the capacity for mate choice, every animal species would then evolve some sort of fitness indicator; and that some indicators might be costly, exaggerated body parts, and others would be costly, ritualized courtship behaviors. But we could not have predicted that courtship behavior would reach an especially high degree of sophistication exactly 535 million years after the Cambrian explosion (when multicellular animals proliferated) in our particular species of bipedal ape. Nor could we have predicted that the courtship behavior would take the precise form of interactive conversations using arbitrary acoustic signals (words) arranged in three-second bursts (sentences) according to recursive syntactic rules. Perhaps it could have happened in an octopus, a dinosaur, or a dolphin. Perhaps it was likely that it would happen sometime, in some species of large-brained social animal. Rewind the tape of evolution, and the human mind would probably not have evolved, because sexual selection would have taken a different contingent route in our lineage of primates. But I suspect that in any replay of evolution on Earth, sexual selection would sooner or later have discovered that intelligent minds similar to ours make good courtship ornaments and good fitness indicators.

Emphasis mine.

Hegel's philosophy of history

While I was on the bike at the gym today, I read the chapter on Hegel's philosophy of history in Herbert Marcuse's book Reason and Revolution. This is probably the most derided and dismissed part of Hegel's philosophy, maybe even more so than his philosophy of nature, owing to what some take to be its political and moral implications. As Marcuse himself puts it:

Hegel's picture of the Reformation is fully as erronenous as his description of the subsequent social development, confusing the ideas by which modern society glorified its rise fo the reality of this society. He was thus led to a harmonistic interpretation of history, according to which the crossing to a new historical form is at the same time a progress to a higher historical form—a preposterous interpretation, because all the victims of oppression and injustice are witness against it, as are all the vain sufferings and sacrifices of history. The interpretation is the more preposterous because it denies the critical implications of the dialectic and establishes a harmony between the progress of thought and the process of reality.

I'm not really in a position to refute Marcuse on this point, not being familiar enough with the text he's interpreting. What he's saying sounds true. From the perspective of the current order (whatever it may be), there is going to be strong pressure, just by virtue of being embedded in the culture, to view everything that has come before as not only leading up to the current state of affairs but also justifying it and making it appear rational. It's one thing to say that the basic categories by means of which we understand history—justice, freedom, and emancipation—could not have come about but through the experience of humans of their opposites (injustice, slavery, and oppression). It's quite another thing to say this makes history rational and thereby justified. This is the move that Marcuse calls a "harmonistic interpretation of history". The philosopher's job is not to justify or rationalize what has come before and what exists now. It's the opposite. It's to engage in the act of immanent critique, by means of which the highest categories of civilization are turned against civilization itself. It's only by means of the most ruthless self-criticism that we arrive at the self-consciousness which Hegel sees as constituting the ultimate law of history.

And that law of history is, I believe, more or less correct. It's the idea that universality means something, i.e., is a real historical force, when individuals self-consciously understand themselves as acting in accordance with it. The whole point and purpose of history is so that individuals understand themselves as acting in accordance with notions of freedom, justice, equality, and the like. Hegel's understanding of history is in an important respect a Kantian one, in that there are always two, not one, preconditions of rational action: I must act in accordance with the notion, but I must always also take myself to be acting in accordance with the notion. Anything else is mere mechanism. This is why, according to Hegel, history is the story of man's emancipation from and domination over nature. Again, it's a basic Kantian move. The given (be it nature, the thing in itself, or the local Catholic bishop) has no intrinsic authority for freedom. Whatever authority it gets it gets by means of the free act of reason.

In my opinion the major metaphysical (as opposed to moral or political) weakness in Hegel's philosophy of history (at least as explained by Marcuse) is in Hegel's understanding of the relationship between historical change and natural change. As Marcuse puts it:

Since Aristotle, historical change has been contrasted with changes in nature. Hegel held to the same distinction. He says historical change is 'an advance to something better, more perfect,' whereas mutation in nature 'exhibits only a perpetually self-repeating cycle.' It is only in historical change that something new arises. Historical change is therefore development. (emphasis mine)

As Aristotle puts it in Physics B1, "[W]hen we speak of nature as being a generation, this is a process toward nature [as a form]." From the time of Aristotle but until roughly the time of Hegel, the process of nature was understood as roughly cyclical in kind. It was an imperfect replica of the perfect cyclical generation of the heavens. While species occasionally passed into and out of existence (the Greeks knew of fossils), the overall tendency was for nature to "keep with itself". So humans give birth to more humans, deer give birth to more deer, acorns eventually become acorn-bearing oaks, the Nile flooded according to schedule, etc. This idea was under attack in Hegel's day, but it wasn't really until the publication of Charles Darwin's The Origin of Species that people began to realize the extent to which the opposite position was true. Even Darwin wasn't aware of the extent to which nature generated novelty. He thought the entire process leading up to humans might have transpired over the course of a few million years. We know now the process was several orders of magnitude greater. The Earth is about 4.5 billion years old.

The implications of this for the philosophy of history are staggering. Hegel thought going back to the beginning meant going back to the Greeks or to "oriental" society. We know now that Hegel's history covers approximately 1% of the actual history of mankind. But apart from the mere quantitative adjustment, there is a qualitative one, too. Evolution makes it impossible to regard human history as constituting a realm entirely separate from that of natural history. On the one hand, we now know that nature generates radically new forms. Evolution is the original avant garde modernist. On the other hand, it no longer makes sense to think of the human act of creation (be it artistic or technological or otherwise cultural) in abstraction from the tendency of nature to increase in complexity and in order. The transition from genetics to memetics in human beings does not designate a radical break with nature but rather a smooth continuation of this increase in complexity and order toward an as-yet unrealized terminus.

Historical change and natural change appear to be two species of the same genus, and so neither reduces to the other. The genus appears to be change itself, or time, which is not an empty form as Kant thought, but which has a rational structure. As Marcuse explains:

The work of thought was destroyed by thought. Thought is thus drawn into the process of time, and the force that compelled knowledge in the Logic to negate every particular content is disclosed, in the Philosophy of History, as the negativity of time itself. Hegel says: 'Time is the negative element in the sensuous world. Thought is the same negativity, but it is the deepest, the infinite form of it...'

As Hegel argues repeatedly, negation is not mere destruction but rather determinate negation. It is an annihilation which remembers and builds upon what it annihilates. A community or way of life does not merely come into existence. It kills the parent-society that gave birth to it, and it understands itself and justifies its way of doing things in contrast to the previous way of doing things. Modern society is a rational society that takes itself to be rational for rational reasons! (Enter Nietzsche and Adorno here...) Whether or not you buy into all these trappings about rationality, though, this much is true: people in a society have a shared memory or history which constitutes who they are. Furthermore, it constitutes how they reflect upon that identity—which especially in the United States has huge implications for the critique of racial, gender, and sexual identity.

What I'm suggesting is that there is an analog for this in nature. All life based on DNA "records" everything that has happened to it so far in the evolutionary process. Every species in existence today is a descendant of one, common, universal ancestor, the basic chemical traits of which we still all possess. That genetic information gets expressed in an organism which gets acted upon by an environment, which in turn causes the organism's genetic information to change over the long-run. Those organisms in turn impact and change the environment in drastic ways (the oxygenation crisis, the snowball earths, etc.), resulting in a dynamic feedback loop. This is precisely why the evolution of life has been accelerating. It's a result of (a) the ability of nature to store and destroy information and (b) the dynamic feedback loop between nature and itself as it acts on this information (blindly carrying out those instructions). Eventually large brains allow for greater memory and self-conscious, rapid information storage and retrieval. The invention of culture causes an increase in the order and complexity of information in the universe, but it does more than that. For once, the instructions don't have to be carried out or destroyed blindly. The information can be used and changed consciously, in accordance with other experiences. Language allows people to share these experiences and information with one another in one life time. The arrangement of the information is more ordered and complex now than previously, but a qualitative change is also taking place with the introduction of consciousness. Information has now become knowledge. Knowledge allows me to act upon my own experience, rather than waiting for nature to do it over the course of many generations. I direct myself by means of knowledge only if there is a self to mediate the relationship. Thus, individual subjectivity. Yet only agriculture allows societies to grow much larger than they could before. This in turns sets the stage for the complex social relations that give rise to what Hegel calls Geist: the relationship in and through which individual subjectivities are validated as subjectivities, but which is constituted by those very same subjectivities. And that's where Hegel's story takes off.

The fact that Hegel is blithe about history being a "slaughter bench" and that there are people who are "outside of history" is distracting, to say the least. But I think a proper understanding of the world requires something like Hegel's account. The main problem with it—once you get past the 19th century German-isms in it—really isn't in the account of history so much as it's in the account of nature behind it. The quote about time being the negative element in the natural world comes very close to the truth. The problem is with seeing nature as a less perfect form of thinking. That's a remnant of the old Aristotlean idea that the earth is a less perfect image of the stars, and the stars are an image of pure thought, so therefore life is an imperfect image of pure thought. That's where you get a lot of weird teleology and retroactive justification. I think the correct view is that, as Aristotle said, nature is form [morphe and therefore eidos or "idea"]. But once the last universal ancestor came into existence (and perhaps before), nature developed the ability to act destructive upon itself. It could "negate" itself. (And by the way, this is why Wolfram's cellular automata can't really explain why we have thought and culture and jazz and whiskey. It's because there's no dynamism in cellular automata. You need to introduce evolutionary algoritms. These cause the laws (the "forms") by means of which the automata act to themselves change. This is precisely the destructive, reflexive ability nature already has after the LUA.) And that's the key right there. That's why you can get from cyanobacteria to Mahler. That's why you can eventually get from the blind destruction and creation of information in "brute" nature to the self-conscious construction and use of knowledge in a human being. It's because nature isn't just "form" or "in-form-ation". It's because—for whatever reason—nature is already reflexive.