Walking and talking

[Brian MacWhinney]

Dear Info-CHILDES,
  So far, it appears that the evidence for a dissociation between walking
(and other motor development) and talking is not panning out.  However,
before concluding this discussion on that note, let me throw in one other
pointer and one reflection.  First the pointer.  Moshe Anisfeld at Yeshiva
began working on this about 15 years ago.  He believed that, using more
microgenetic methods, one could discern some tendency for the child to focus
on a single skill at a time.  Although I read several initial papers from
Anisfeld on this, I never saw anything very definitive in published form.
Moreover, I find nothing in the CHILDES online bibliography from Anisfeld on
this issue.  So perhaps he never found anything.  At the least, it seems to
me, he was taking a close look at this.  If, after taking such a close look,
one finds nothing, then perhaps one can indeed conclude that there is
nothing there.
  The other side of this matter is the fact that it seems to me that there
is a group of people that ought to be at least a bit worried about the
absence of this effect.  This group is composed of people who believe in the
modularity of mind along with limits on cognitive processing.  If the mind
is modular and if the resources for cognitive processing are at least
somewhat limited, shouldn't the attainment of rapid advances in one area
come at the expense of advances in another?  For example, if I am taking a
load of three courses at college, shouldn't I do better at these three
courses (ceteris paribus), than if I overload with six courses?  Wouldn't
this be the same for the infant?
  The clear alternative here is that progress in one of these domains
actually supports progress in another.  In this sense, the mind would have
at most some weak level of permeable modularity.  If the child can walk
about more, they can grasp more things and learn their names.  If they can
learn the names for things, they can activate their images and have greater
desire to grab them and walk and crawl about with them.

--Brian MacWhinney