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<font size=3>I have enjoyed the recent discussion about baby signs and
wish to underscore the point of Adele Abrahamsen's message: that
the debate over IQ effects overlooks the really important aspects of
Acredolo and Goodwyn's work, which spoke more to the debate on whether
early signing and/or gesturing in oral/aural children would somehow
impede their spoken language development.<br><br>
I organized and edited a special issue on children and gesture for the
<i>Journal of Nonverbal Behavior</i>, published in 2000 (summer issue,
vol. 24). The Acredolo and Goodwyn team have two papers in that
issue, the most pertinent to the discussion here an experimental design
(co-authored by Catherine Brown) of 11-month-old infants randomly
assigned to three different conditions of varying levels of parental
(signed and spoken) input. <br><br>
An excerpt from their Discussion: "The results...particularly
the comparisons between the Sign Training group and the Non-intervention
Control group, strongly support the hypothesis that symbolic gesturing
facilitates the early stages of verbal language development.... infants
who augmented their fledgling vocabularies with symbolic gestures
outperformed those who did not. The fact that no such advantage was
found for the infants in the Verbal Training group provides reassuring
evidence that the superior performance of the ST infants was not simply a
function of their families being involved in a language-centered
intervention program. The explanation seems to lie instead within
the gesturing experience itself."<br><br>
I have no dog in this fight, not even a puppy in the scuffle, but I write
simply to encourage interested parties to read this fine paper and return
to, as Adele suggested, the real points of their work. In this 2000
paper there is no measurement or discussion of IQ but the measurement of
many language indices longitudinally at 15, 19, 24, 30, and 36
months. (Would that our field featured more <i>longitudinal</i> and
<i>experimental</i> designs, of <i>any</i> developmental
phenomena!)<br><br>
Chris Boyatzis<br><br>
At 10:56 PM 10/18/2007, Adele Abrahamsen wrote:<br>
<blockquote type=cite class=cite cite="">The claim of later IQ effects
unfortunately distracts from the most<br>
important impact of Acredolo and Goodwyn's work.<br><br>
It was long assumed that manual symbols would compete, and hence<br>
interfere, with spoken words. In my own research on what is now
called<br>
baby sign, initially I could offer potential participants nothing
more<br>
than indirect evidence and reasoning to the contrary. So I was
delighted<br>
when Goodwyn and Acredolo (1993) provided compelling direct evidence
that<br>
baby signs do not interfere with acquisition of spoken words.
Moreover,<br>
regardless of whether baby signs facilitate spoken words, clearly a
baby<br>
who acquires them has more symbols available for use. (E.g., a
reanalysis<br>
of G&A's data in Abrahamsen 2000 showed a median of 5.8 gestures when
the<br>
median number of words was 5.9; for those toddlers with no overlap,
that<br>
doubled the number of meanings that could be expressed through symbols
at<br>
that time.) There also is a hard-to-predict subgroup of toddlers for
whom<br>
baby signs carry much more than half the communicative burden for
several<br>
months, which would seem to be advantageous.<br><br>
It is much more challenging to determine the extent to which, if at
all,<br>
baby signing results in facilitation of spoken language or general<br>
development. To their credit Acredolo and Goodwyn included
longitudinal<br>
comparison groups in their design, but as Brian and Kathy noted, the<br>
results raised more questions than they answered. Ideally someone
would<br>
step up and do a replication study with a larger number of randomly<br>
assigned or closely-matched participants.<br><br>
Meanwhile, it would be sensible to base the decision to enhance
gestural<br>
input to a baby on practical considerations (e.g., is there a
caretaker<br>
who would enjoy doing it?) and on those outcomes for which there is
ample<br>
evidence (e.g., a modest, possibly temporary increase in the number
of<br>
symbols when both gestures and words are counted). There is no need
to<br>
reach beyond this to apparent effects that are large or of long
duration<br>
and for which there is no obvious mechanism, such as the claim of a<br>
12-point IQ boost at 8 years. (Evidence and plausibility of
verbal<br>
facilitation lies between these extremes.)<br><br>
Isabelle Barriere made the interesting point that, even as parents
of<br>
hearing toddlers buy videos and take baby sign classes, the old
worries<br>
about interference live on recommendations to parents of children
with<br>
cochlear implants. I would add that the issues and relevant studies
extend<br>
far beyond the baby sign literature, especially with respect to<br>
syntactically structured language.<br><br>
> Dear Info-CHILDES,<br>
><br>
> During the flurry of discussion
of the C/P contrast, there was<br>
> an message from Mechthild Kiegelmann that seemed to slip under the
radar<br>
screen. This message summarized replies to a query about Baby
Signs. I<br>
spent some time tracing the various web links involved and I would like
to<br>
draw colleagues' attention to one issue in this<br>
> research that troubles me. This is the status of a report
by<br>
> Acredolo and Goodwyn, which is cited prominently at
<a href="http://www.babysigns.com/" eudora="autourl">www.babysigns.com</a>
<br>
and
<a href="http://www.signingtime.com/" eudora="autourl">
www.signingtime.com</a> (STResearch_Summary.pdf). This reports<br>
> speaks of a 12 point "increase" in IQ measured at age 8
for children who<br>
are taught Baby Signs when they are toddlers. Interestingly,<br>
Mechthild's links also point to an article from the Canadian Language
and<br>
Literacy Research Network by J Cyne Johnston, Andrée Durieux- Smith,
and<br>
Kathleen Bloom that challenges the claims of this study by noting that
it<br>
provides no description of subject recruitment<br>
> provedures, attempts at random assignment, or evidence of any<br>
> pretesting. They conclude that, "The high accessibility
of a wide range<br>
of baby signing products is not matched by good quality<br>
> evidence that would reinforce manufacturers' claims."<br>
> It is worth adding that
the groups were already different when<br>
> the Bailey was given at 24 months, but this is presented not as<br>
> evidence of initial group differences, but rather as the result of
the<br>
initial effects of the treatment. The relevant study was<br>
> presented as a conference paper at ISIS in 2000, but has never
been<br>
published in a journal.<br>
> I have mixed feelings about the plausibility
of this result. I<br>
> certainly do not view IQ as immutable and genetically-given. I
am also<br>
quite convinced that Baby Signs provide an excellent method for<br>
achieving early and rewarding communications with toddlers.
However, I<br>
find it difficult to believe that a program in Baby Signs alone
could<br>
achieve a 12-point increase in IQ when several years of Head Start lead
to<br>
nothing measurably permanent.<br>
> I hope that academic researchers take these
unpublished claims<br>
> with a healthy grain of salt. If there are newer studies
supporting<br>
these claimed gains in IQ, I would love to learn about them.<br>
><br>
> --Brian MacWhinney, CMU<br>
></blockquote>
<x-sigsep><p></x-sigsep>
Chris J. Boyatzis, Ph.D.<br>
Associate Professor of Psychology<br>
Department of Psychology<br>
Bucknell University<br>
Lewisburg PA 17837<br><br>
Office phone: 570.577.1696<br>
FAX 570.577.7007<br>
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