A few years back Derek Bickerton published a book called Adam's Tongue which I reviewed in three posts (here, here and here). That book was disappointingly breezy, a lively account that made bold assertions and brushed objections aside with the swat of a hand. Say this for the guy, he's willing to keep plugging. Earlier this year he published an entirely non-breezy account of his theory: More than Nature Needs — Language, Mind, and Evolution. After reading the book I went back and read my old posts on the first work. I find that the theory has changed only a bit but the process is much more clear.
Step 1 – Escape from the here and now
His theory still begins with the rise of the African savanna about 2 million years ago. The human lineage of that time was unable to bring down much game and was forced to feed on the conveniently dead. That task involved "confrontational scavenging" for driving off others from the scene. Groups of protohumans worked as a team, fending off the other scavengers. These rivals, by the way, include lions, hyenas, wild dogs, jackals, large birds of various sorts like vultures and marabou storks, and the occasional leopard and cheetah. Some of these animals, notably lions and hyenas, might not have been so easy to chase off. Just as today you can see hyenas keeping their distance while the lions feed, our ancestors may have had to wait patiently while the big boys satisfied themselves. Anyway, there seems no reason to doubt that our ancestors did a lot of scavenging of the confrontational kind, and when confronting stronger rivals, it helps to be more than one.
Bickerton compares the task of scavenging to that of a bee that has found a flower field. The bee flies back to the hive and "recruits" others by telling them where the flowers are to be found. The same thing happened on the savanna. An ancestor found a carcass and returned to recruit others to join in on the confrontation. The recruitment was originally accomplished by a combination of grunts and gestures, anything that would get the idea across. It reminds me a bit of the scenes in faithful-dog movies where the boy says, "I think Shep wants us to go with her." It would be unfair to press hard for details, but there is one thing I think needs clarification. Which came first, the cooperation or the recruiting? After all, bees don't just go looking for any old bees to join in on the pollenating. They return to an existing hive with an already established eusocial order. I don't have the citation, but I'm guessing the eusociality is older than the bee's waggle dance.
I have been to a surprisingly large number of settings that include carcass, scavenger, and savanna. The confrontations are not just between species. Hyenas quarrel amongst themselves as well. It is not at all unusual to see a hyena steal a meaty leg from a fellow hyena. Humans are really unusual in the way we are most social over meals, the time other animals are most individual. So this theory of Bickerton's needs some tightening about the rise of human communities.
None the less, just as bees can tell other bees about flowers off somewhere beyond bee senses, our ancestors began to tell one another of carcasses to be found yonder.
Step 2 – Brain changes
Presumably the gestures and grunts beckoning to a distant carcass quickly became stereotyped so that something like ooog meant big carcass and baaa meant little carcass. Symbolism of this sort arises naturally because the words mean something that must be evoked rather than pointed at. So there is no need for a genetic mutation to support symbolic thinking. Likewise, the brain is plastic enough to reform synapses and make efficient circuitry so that symbols can be generated and understood more quickly and efficiently than at the start. Thus, we do not need natural selection to account for quicker use of symbols.
On the other hand, the brain did not just reorganize itself to handle symbolic circuitry. The fossil evidence is as clear as it can be that the brain grew, and grew rapidly. Growth like that does not just happen. In terms of energy, the brain is a very expensive organ. Any growth in the brain constitutes a permanent commitment to supplying the extra energyneeded to support it. To keep that commitment (a) new energy sources must be found, and/or (b) the body has to make a trade-off and reduce the energy expended elsewhere. We probably did some trade-off; our arms, for example, are much weaker than ape arms. But apes are already pretty smart and have made most of the trade-offs than can be made without reducing their survivability.
New energy sources could come from increased meat eating, cooking the food, and the benefits of cooperation. But new energy sources don't automatically lead to increased brain size. Lots of organs have evolved to bigger size. Wrens and storks have similar feet, but the stork's is much bigger. That is accomplished, not by redesigning the foot so much as by building it for a longer period of time. The stop-growing-feet button is not pressed until much later than the wren's. If we assume something similar lies behind our brain growth, there must have been a similar delay in pressing the stop-growing-a-brain button. That kind of change demands some alteration of the DNA and the preservation of the change demands selection. That pressure for growth may not have been language, but our ancestors were pressed to get smarter. An automatic rewiring of the brain cannot be the whole story.
Also, language does not live by symbolism alone. The original carcass-recruiting pidgin that Bickerton imagines had a natural limit. There was a vocabulary for carcasses: zebra, gazelle, giraffe… on up to some small number. There might be another warning vocabulary: be on the lookout for lions, hyenas… and on to some small number. A third vocabulary might be devoted to directions: that way, by the hill, near the stream… on up to some finite number. So a savanna dweller could report: zebra, beware of lions and hyenas, that way near the stream. That pretty well covers the news. We would now be as advanced as bees with a waggle dance.
Bees went no further. "But," says Bickerton,, "the effects of displacement or organisms with minuscule brains must surely be different in brains that are orders of magnitude bigger, that can hold finely dissected descriptions of the world…" [chap. 9]. But it takes more than big brains to go beyond the waggle dance. You have to introduce new topics. Bees never waggle a route to a fine view of the valley. They don't care about that. Now suppose the savanna scavenger is amused to see a zebra chase off two lions and a hyena. He has the words and gestures to report the incident to his fellows, but why should he add a new topic? Something like that must have happened, however, for languages grow more by adding new topics than by dissecting existing ones. Bickerton pays no attention to the growth of topics, let alone the growth of kinds of topics that require subjective awareness and metaphors.
Did you notice the ellipsis at the end of the passage I quoted? Let's peek at the rest of Bickerton's sentence. Humans did better than bees because, "… [they] constantly engage in something unknown to ants and bees, rich and varied patterns of social interaction between highly individuated animals." So without the familiar by-your-leave he has slipped in the whole of human community—the trust, the gossip, the moral codes, the resolution of hurt feelings, and the finding of new things to talk about. He just takes the whole communal society for granted. Was there no involvement of language in any of that? At one point he grumbles about "vague" theories of co-evolution of language and humanity, but he really cannot get away with just brushing aside the transition from savanna scavengers to biologically-unique, human communities.
Yet brushing the whole thing aside is exactly what he tries to do. From two million to one hundred and fifty thousand years ago we had scavengers, symbols, and brain plasticity.
Step 3 – Buy into Chomsky
Then came a step beyond placing words one after another like beads on a string: the emergence of universal grammar with its hierarchical structure.
So at the end that Bickerton reveals himself to be less than a full heretic in Chomsky's Church. He believes externalization came first in the form of a protolanguage, but buys most of the rest. Chomsky calls the emergence of universal grammar "a great leap forward." Bickerton likens it to riding an escalator, and he buys Chomsky's main points: that the reorganized brain is more efficient at thought than at communicating (i.e., telling one another things), that a universal grammar is language-exclusive, and that natural selection wasn't necessary for the coming of a universal grammar. (He does offer, by the way, an invaluably succinct account of universal grammar.)
I could go into more detail, but just last month I posted reports (here and here) on a paper by Maggie Tallerman that rebuts the points, so why bother repeating them? I have always loved Bickerton's work on creole languages and feel utterly let down by the impoverished view of humanity that he and Chomsky espouse. Creationists may think that natural selection devalues humanity, but it is really physicalism without selection that sells us for scrap.