Craig Sailor sent me
this link to a paper in Nature that
argues for a correlation between the gradual emergence of a certain kind of
stone tool and the emergence of language. As Caig put it in his note to me:
"They
suggest a causal relationship: the skills required to create the tools in
question are complex enough that verbal instruction was significantly more
effective than imitation (which they support with experimental evidence),
meaning the gene(s) responsible for communication were preferentially selected
for in the environment, leading to the general evolution of language."
They actually
contrast five kinds of "transmission" mechanisms. Goring form the
least interactive to the most they consider (i) Reverse engineering (subject
given stone and tries to figure out how it was made) (ii) imitation/emulation
(subjects watches someone make the stone and tries to copy this), (iii) basic
teaching (proficient maker guides learner but no physical interaction), (iv)
gestural teaching (teacher molds gestures of learner on stone) and (v) verbal
teaching (teacher instructs learner by talking). The results of the
experiment are that one finds better and better information transmission as one
moves from (i) through to (v). In other words, as regards EVOLANG
concerns, providing instruction via talking really helps. The suggestion is
that "tool making created a continuous selective gradient from
observational learning to much more complex verbal teaching…the more complex
communication allowed the stable and rapid transmission of increasingly complex
technologies, which in turn generate selection for even more complex
communication and cognition, and so forth (5)." As the authors note (there
are 12 of them). Their results place "little necessary constraint on when
teaching and language may have evolved…" though they wish to suggest that
this evo pressure of the indicated cline started having some effect at least
2.5 mya.
Some comments: It's
pretty clear that the authors want to say something here about the evolution of
our NL capacities (indeed, this is
what made the results popular science newsworthy (see here)). However, so far as I can tell they do
not isolate what specific linguistic features are required to juice the tool
building transmission system. One can imagine a very limited
"language" that would suffice (e.g. do this, like this, etc) to
produce good tools and tool making instructions. And if this suffices to
get good tool making and good tool making teaching then it is unclear what
explanatory mileage one can get form this experiment. Said another way, the
"proto-language" gestured to above (which strikes me as quite
possibly sufficient for the tool making purposes discussed) is a very far cry
from Natural Languages. And though, I am willing to grant that the more complex
the language structure (both wrt word meaning and the combinatorics) the more
information one can transmit, and the greater the complexity of the
transmittable information the more complex the teaching that it can support, I
do not see how this explains the emergence of FLs with the characteristics found
in NLs. Or, to put this more charitably, I do not see that languages with the
two basic features that we have discussed (here
and here)
are necessary for making tools. Note that I have no trouble seeing how the emergence
of more and more complex linguistic systems can support more and more
sophisticated teaching, but that does not support the causal direction of
interest. The causal direction needs to be from tools to language not from
language to tools.
Let me note two
points: First, that unlike much of what passes for EVOLANG this work aims to
give an account of how linguistic capacity
evolved. The idea is that it piggy backs on selective advantage of tool making.
This is good: it's heart is in the right place. Unfortunately, second, the
paper is actually a nice example of the failings of much of the EVOLANG
literature that I have looked at in that it never actually specifies what it
takes to be the necessary features of languages required for the task at hand.
Would the capacity to form simple NVN strings suffice? Would words that adhered
to RD suffice (btw, I can't see why not on both counts)? Do we need unbounded
hierarchically recursive structures to get flint tool making off the ground?
Who knows? The problem is not that the paper doesn't address this
issue, but it doesn't even recognize its relevance.
Let me end by stating
again what someone like me (and I suspect you too) want out of an EVOLANG
account: how did our linguistic capacity arise? Which one is that?
Well, for starters, where did the linguistic capacity with the two key features
Chomsky discussed in the above linked to articles come from? Isolate
the features of language without which tool creating transmission information
is impossible.[1]
That's a first step. The second is to show that the causality is from tools to
language capacity, rather than the other way around. So, sure there is a
correlation: more complex tools goes with more complex language, but more
complex everything goes with more complex language. So big deal.
Let me say this
another way: the paper, taken at face value, suggests that some kind of
communication system would have been useful in making the flint tool discussed.
However, as noted this does not imply that on had an NL like ours earlier than
75-50 kya. It only says that it would have been useful. But quite possibly
(likely) a more limited communication
system with properties quite unlike those found in our NLs would have been just
as useful for this task. Nor is there
any reason given why having such a more primitive system is a causal precondition
for having ours. And therefore the relevance of the results completely escapes
me. Here is yet another case where not describing the properties whose
evolution you want to explain has led to a whole bunch of time intensive hard
work being done with no obvious gain in insight. In sum, this looks like another
case of those things not worth doing are not worth doing well.
