So it might not be a lack of innovation so much as a lack of imitation or teaching; if these were as rare in recent hominids as they are in apes, the breakthrough at 50,000 years might not be innovation so much as the ways in which it is culturally sustained for long enough to show up in the archaeological record.  But Tomasello’s escape clause still suggests that technological creativity wasn’t very important in evolution until quite recently.

Creativity for language instead?

Since the distinction of anatomically-modern from behaviorally-modern humans was made, the usual explanation has been (Oakley 1951) that language arrived on the scene and changed everything, including creativity.  That’s the most common explanation offered for what happened about 50,000 years ago.

       A more refined version of it (Bickerton 1990, Calvin & Bickerton 2000) says that protolanguage (the vocabulary and unstructured short sentences of modern two-year-olds) could have been gradually developing for a million years – but that the big step up to long, complex sentences (which require structuring by syntax to be disambiguated) is what comes late, somewhat before 50,000 years ago.

        Yet language itself is just another example of creativity, once you move beyond stock phrases and start to speak sentences that you’ve never spoken before.  That means you have tried out word combinations, judged them for coherence, and likely improved them offline before uttering them.  Thus, some of the most impressive feats of creativity are not even seen as innovation because we all seem to do them so effortlessly.

        While language surely makes it easier to spread around the results of creativity and build atop what others have tested, what we really want is the source of both language and non-language creativity.  Here I will consider the demands that off-line innovation places on brain circuitry – and how think-first creativity might have taken a major leap forward about 50,000 years ago without any concomitant increase in brain size.  Think-first creativity requires a number of abilities, but let me start with planning abilities in general.

When an advance plan is needed

We anticipate our next handhold in climbing a tree, but the really hard versions are when you have to plan multiple stages of the action in advance, rather than just groping your way along while guessing one stage ahead.  The driver who uses grand slalom tactics in freeway traffic, leaving a trail of flashing brake lights in his wake, does not really need higher intellectual function to assist him, only the apelike abilities to swing through the trees, looking ahead to the next handhold.  Planning in depth is what I am focusing on here, what you need to imagine several preparatory stages, testing each one off-line and then imagining them one after the other.

                 Outside of the half-hour time scale of intentions, chimps don't seem to prepare for tomorrow.  Innovation is also infrequent and there is no evidence for an ape planning a novel course of action in any depth.  If chimps could plan ahead, they would be the terror of Africa (and probably extinct by now) – but they're not.  They're aggressive enough, what with their ganglike hit-and-run attacks on an isolated neighbor, five-on-one affairs that leave behind a dying chimp.  With a little foresight added to that aggressiveness, chimps could make war on whole groups of neighbors using stockpiling of supplies, practiced maneuvers, and coordinated attacks.  But no one sees much evidence of planning in the chimps, and certainly not the sort of planning where two or three novel stages have to be worked out in advance of acting – what, in modern warfare, is called “good staff work.”  More common examples are seen when planning a college curriculum or a new crop rotation.

       Learned staging and innovative on-the-fly staging are, perhaps, different things that evolved at different times.  Up until about 400,000 years ago, stone toolmaking consisted of banging away on a stone until it resembled the desired shape, usually one with sharp edges.  Then prepared cores were invented, where first one shape was made and then a series of flakes were struck off of it.  While this is staged, there is nothing novel about each repeat performance, no mix and match or interpolation – and that’s what you need as a setup for on-the-fly creativity that is done off-line as you “get set.”

       Many animals can muddle around slowly, feeling their way.  Our common ancestor with the Neanderthals could likely routinely stage food preparation as well as toolmaking.  But on-the-fly creativity that is done off-line in coherent stages – that’s our big challenge.  And I have a candidate for what might be the setup, a behavior with a lot of immediate payoffs.  It’s not at all intuitive, and even sounds mundane.  It isn’t what our flights of modern creativity lead us to value, but it makes a very good candidate for what might have paid the bills along the way.

Innovation during get-set

What does throwing have to do with creativity?  Flinging in the manner of toddlers is not what I have in mind here, nor dart throws or basketball free throws where the idea is to perfectly reproduce the stereotyped memorized commands.  Chimps throw as a threat, not as a hunting technique, and they are never seen practicing their technique to improve their accuracy or versatility.

       The hard problem with throwing is to use it for targets that are not at one of your standard positions.  Compounding this need to be creative is the need to do it right the first time, as otherwise dinner might run away.  Here is an example of off-line innovation with a big payoff, in terms of calories consumed and healthy offspring.

       Throwing (and other ballistic movements such as clubbing, kicking, and hammering – and, for that matter, spitting) is over-and-done in an eighth of a second.  You simply cannot feel your way into this, as the feedback takes so long.  It takes about an eighth of a second for spinal reflexes to even begin to corrected a perturbation in the arm.  Since a dart throw only lasts about an eighth of a second, it is entirely ballistic, unguided by second thoughts after you start.  So the feel-your-way tactics that most animals use won’t work here, except in the slow positioning that precedes the rapid ballistic movement.

       And planning a throw has some nested stages, reminiscent of syntax.  The highest velocity action is in the wrist movement, but planning it requires you to take account of what the elbow is doing:  wrist flicks, where mistakes matter most, are nested inside elbow uncocking.  Yet elbow planning needs to know what the shoulder is doing, and the shoulder too has a forward velocity due to what the whole trunk is doing.  For any given target distance and elevation, there are a hundreds of combinations of wrist-elbow-shoulder-trunk movements which will get the projectile on target – but they are hidden in a sea of millions of wrong combinations, any one of which will cause dinner to escape.

       You need a coherent plan: all of the plans (and there are about a hundred muscles involved) have to hang together.  And, if the target is not at one of your well-rehearsed distances, you must make a novel, staged, coherent plan.  In this case, throwing isn’t mundane; it is indeed starting to sound a lot like the kind of creativity that we otherwise care most about – and especially like the everyday coherent plans for novel structured sentences.

The Darwinian process

       The problem with creativity is not mixing and matching.  Variability usually comes for free in most biological systems.  Mixups are easy.   The problem is incoherence, where things just don’t hang together properly – as in our nighttime dreams, full of people, places, and occasions that never occur together in real life.  What sort of process does it take to convert that kind of raw material into coherent collections, whether it be an on-target movement program, a novel sentence to speak aloud, or a sculpture?

       The only process we know in nature that routinely achieves coherent results from incoherent raw materials is the one Darwin discovered.  This quality bootstrap is not only seen at work on the millennial time scale of species evolution but also on the days-to-weeks time scale of the immune response.  Can brain circuitry run a version of it on the time scale of thought and action, shaping up a good-enough movement program for ballistic movements?  And perhaps other creative sequences, such as novel sentences?

       It is surprising that so few discussions of creativity focus on the mechanics of this well-known process for successful innovation, particularly when there are not other good examples of an algorithmic quality-improvement process.  Although creativity may seem spontaneous, without perceived antecedents, it may nonetheless reflect an underlying process of the refinement of candidates.

       One can summarize Darwin's bootstrapping process in various ways.  A century ago, Alfred Russel Wallace emphasized variation, selection, and inheritance.  (It reminds me of a three-legged stool:  evolution takes all of them to stand up.)  But as I explain at more length in A Brain for All Seasons (from which this section is adapted), there are some hidden biological assumptions in that three-part summary.  When trying to make the list a little more abstract to encompass non-biological possibilities, I wound up listing six ingredients that are essential (in the sense that if you're missing any one of them, you're not likely to see much progress):

Try leaving one of these out, and your quality improvement lasts only for the current generation – or it wanders aimlessly, only weakly directed by natural selection.

       Many processes loosely called “Darwinian” have only a few of these essentials, as in the selective survival of some neural connections in the brain during development (a third of cortical connections are edited out during childhood).  Yes, there is natural selection producing a useful pattern – but there are no copies, no populations competing, and there is no inheritance principle to promote “progress” over the generations.  Half a loaf is better than none, but this is one of these committees that doesn't “get up and fly” unless all the members are present.

Speeding up the Darwinian process

       And it flies even faster with a few optional members.  There are some things that, while they aren't essential in the same way, affect the rate at which evolutionary change can occur.  There are at least five things that speed up evolution; while I will use examples from the outside world to illustrate them, they all have counterparts in the brain circuitry for running the Darwinian process.

       First is speciation, where a population becomes resistant to successful breeding with its parent population and thus preserves its new adaptations from being diluted by unimproved immigrants.  The crank now has a ratchet.

       Then there is sex (systematic means of creating variety by shuffling and recombination – Don't leave variations to chance!).

       Splitting a population up into islands (that temporarily promote inbreeding and limit competition from outsiders) can do wonders.

       Another prominent speedup is when you have empty niches to fill (where competition is temporarily suspended and the resources so rich that even oddities get a chance to grow up and reproduce).

       Climate fluctuations, whatever they may do via culling, also promote island formation and empty niches quite vigorously on occasion, and so may temporarily speed up the pace of evolution.

       Some optional elements slow down evolution:  “grooves” develop, ruts from which variations cannot effectively escape without causing fatal errors in development.  And the milder variations simply backslide, so the species average doesn't drift much.  Similar stabilization is perhaps what has happened with “living fossil” species that remain largely unchanged for extremely long periods.

       Are there brain circuits capable of running this sort of Darwinian process on the time scale of thought and action – say, milliseconds to minutes?  That was the topic of my 1996 book The Cerebral Code  and, while the answer appears to be yes for the recurrent excitatory circuits of the superficial layers of neocortex, we still don’t know how much of the neocortex makes use of this ability and when.  Once, during a period of fetal or infant tune up?  All the time, in all areas of neocortex?  Where and when await experimental evidence, and the more interesting question – how to you make subroutines out of the successful plans, so as to avoid running through the whole Darwinian copying competition on subsequent occasions – hasn’t been elucidated at all.

New uses for old things

       But let us assume that some brain circuits are capable of running such a process for making multistage coherent plans, and judging them for quality against your memory of what’s reasonable and safe.   Can you use them for other movement sequences than just hand-arm?  Though some of the best-understood regions of the brain such as primary visual cortex seem rather dedicated to a specialty, much of association cortex seems multifunctional.  Certainly there is much evidence suggesting that oral-facial movement planning can overlap with that for hand-arm – and with that for language, both sensory and motor aspects (Calvin & Ojemann 1994).

       When did spare-time uses develop for the movement planning neural machinery for throwing?  Hammering was likely the earliest, though with shared machinery, you can have coevolution with synergies:  better throwing might improve, in passing, the ability to hammer accurately.  And vice versa.

Certainly there is considerable evidence that blending is a mainstay of early childhood thought.  A two‑year‑old child who is leading a balloon around on a string may say, pointing to the balloon, "This is my imagination dog." When asked how tall it is, she says, "This high," holding her hand slightly higher than the top of the balloon. "These," she says, pointing at two spots just above the balloon, "are its ears." This is a complicat­ed blend of attributes shared by a dog on a leash and a balloon on a string.  It is dynamic, temporary, constructed for local purposes, formed on the basis of image schemas, and extra­ordinarily impressive. It is also just what two‑year‑old children do all day long. True, we relegate it to the realm of fantasy because it is an impossible blended space, but such spaces seem to be indispensable to thought generally and to be sites of the construction of meanings that bear on what we take to be reality.

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