Acredolo and Goodwyn’s rebuttal against Nelson, White and Grewe’s Research!


Drs. Linda Acredolo and Susan Goodwyn wrote their response to the recent journal article written by L.H. Nelson, K.R. White, & J. Grewe. This journal article is titled as “Evidence for Website Claims about the Benefits of Teaching Sign Language to Infants and Toddlers with Normal Hearing” that was published in Infant and Child Development, Wiley Online Library, 2012.

I alerted Drs. Acredolo and Goodwyn about this article, and I made a video clip and added captions to make sure that Drs. Acredolo and Goodwyn understand to what I was signing. I posted my video clip to their Facebook page, Baby Sign Language, requesting for their response. Here’s my video clip from YouTube. It is captioned.

You may wonder who are Drs. Acredolo and Goodwyn? Here’s the information.

Dr. Acredolo and Dr. Goodwyn are co-founders of Baby Signs, Inc. and its educational division, the Baby Signs Institute. Both organizations are devoted to helping parents throughout the world experience the many positive benefits that baby sign language with infants can bring.

Linda Acredolo, Ph.D., Professor Emeritus of Psychology at the University of California at Davis, is an internationally recognized scholar in the field of child development. A Phi Beta Kappa graduate of Bucknell University, she earned her Ph.D. at the University of Minnesota’s Institute of Child Development. Linda is a Fellow of both the American Psychological Association and the American Psychological Society. She is a member of Parents magazine advisory board. She currently lives with her husband in Woodland, California.

Susan Goodwyn, Ph.D., Professor Emeritus of Child Development at the California State University at Stanislaus, received her Masters of Science with First Honors from the University of London and her Ph.D. in Psychology from the University of California, Davis. Dr. Goodwyn is considered an expert in the field of child language development and has an outstanding research record, having served as Project Director and Co-Principle Investigator for several longitudinal research projects funded by the National Institutes of Health and the Kellogg Foundation. She currently lives with her husband in Vacaville, California.

Today, Drs. Acredolo and Goodwyn alerted me that they posted their response paper to Nelson, White and Grewe’s paper on their website.

We feel strongly that Nelson, White, & Grewe did not review our NIH-funded research fairly. We stand by our conclusion that signing with hearing babies has a positive impact on verbal development. You can find a detailed, point by point response on our website.

–L. Acredolo, Ph.D. and S. Goodwyn, Ph.D., Co-Founders of the Baby Signs Program

Drs. Acredolo and Goodwyn posted their response on their website.

Response to Research Critique

Whenever a particular idea or research finding becomes so popular that it is frequently cited by others, it almost inevitably becomes the target of “nay-sayers.” Our research on the positive effects of sign language on the development of hearing babies is no exception.

Here’s the PDF file, for you to download and review. PDF File : Response to Research Critique

Thank you, Drs. Linda Acredolo and Susan Goodwyn for taking stand of being our very important allies to the Deaf Community, by promoting, protecting and preserving our most cherished language, American Sign Language.

Amy Cohen Efron

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11 comments on “Acredolo and Goodwyn’s rebuttal against Nelson, White and Grewe’s Research!

Good response by them. I would like to point out, however, that this does not seem to be a formally published response, but one that was only put up on their website.

But thanks for alerting them to white et al’s sneak attack on sign language, in whatever form.

Thanks for sharing this, Amy.

It is common for most, if not all, research to be questioned (I question all research for one). I would like to read the paper that the pro-LSL folks wrote, but you have to pay for it (I am not paying for a ‘likely’ biased paper that says some other research was 90% anecdotal evidence). Here’s an abstract of the paper pasted below:


The development of proficient communication skills in infants and toddlers is an important component to child development. A popular trend gaining national media attention is teaching sign language to babies with normal hearing whose parents also have normal hearing. Thirty-three websites were identified that advocate sign language for hearing children as a way of promoting better developmental outcomes. These sites make several claims about the positive benefits of teaching hearing infants and toddlers to sign, such as earlier communication, improved language development, increased IQ, reduced tantrums, higher self-esteem, and improved parent–child bonding. Without endorsing or disparaging these claims, the purpose of this article was to evaluate the strength of evidence cited on websites that promote products to teach young children to use sign language. Cumulatively, 82 pieces of evidence were cited by the websites as supporting research. However, over 90% of these citations were opinion articles without any supporting data or descriptions of products and only eight were empirical research studies relevant to the benefits of teaching sign language to young children with normal hearing. Unfortunately, there is not enough high-quality evidence cited on these websites to draw research-based conclusions about whether teaching sign language to young children with normal hearing results in better developmental outcomes.

In any case, I thank Acredolo and Goodwyn for their research work. I think the biggest issue is the perception among pro-LSL folks that ASL = Bad verbal language development in deaf babies. If it can be conclusively proven that ASL does not impede verbal language development, it will encourage parents of deaf babies to incorporate ASL into their child’s development.


Well, of course this whole discussion is about signing with *Hearing* babies, not deaf.

When it comes to deaf children, there is a centuries-long “natural experiment”. A “natural experiment” is a situation where circumstances that you would like to examine occur naturally, or where people have set up the desired conditions for reasons that may have nothing to do with the questions you want to test.

The “natural experiment” about which I’m talking is deaf children of Deaf parents. These children grow up in a signing environment, and have historically done better than deaf children of Hearing parents by almost every measure you can use. Historically (up until recent decades), Hearing parents have rarely signed with their deaf children. Even though Deaf families could be considered “disadvantaged” or “at-risk” because they were(are) far poorer on average than Hearing families, their children have done better than deaf children from wealthier Hearing families.

Socioeconomic status of a child’s family continues to be a major influence in a child’s success at school and in working life. Even though Deaf families have lower economic status, their Deaf children have had superior success in school and working life – they are leaders in the Deaf community. This difference seems to have been vigorously ignored for decades. I cannot think of a reason that does not include bad motives.


VERY GOOD point(s), David!

amy – thank u for reaching out the the researchers and getting their response and sharing it here.

interesting they used the term “naysayers”

much peace


I would love to see Dr. Acredolo and Dr. Goodwyn’s paper and as it is, I’m not going to spend $$ to read it. I think the abstract covers what we need to know.

Since it’s about how hearing babies benefit from ASL, it does not necessarily applies to deaf babies. I know deaf babies benefit MORE with ASL or sign language than hearing babies do.

I look at Nelson, White and Grewe’s Journal article as a challenge for others to do better research that will hold its ground.

Nelson, White and Grewe’s abstract said:

“the purpose of this article was to evaluate the strength of evidence cited on websites that promote products to teach young children to use sign language.”

That is all it is.

Ergo, this is an indicator that evidence need to be stronger, thus, researchers need to do better. The article does not indicate to me that they’re saying that parents should not look to sign language aka ASL for their hearing babies and that there is nothing there about deaf babies so, I don’t see how it would influence decision making on the part of parents with deaf babies.

I do not see Nelson, White and Grew’s article as an indication that ASL impedes verbal language.

I do know of ONE parent who regretted using Baby Signs with their baby. This particular parent utilized Baby Signs and regretted it because their baby at 4 years old, refuses to talk. This does not mean that hearing babies are at risk for not being verbal. How many babies out there using Baby Signs are not being verbal when they should be is something that I don’t know and I do not recall seeing this being brought up online or elsewhere. My opinion, could be an isolated situation. I met this parent at a restaurant. The mom was truly devastated and regretted Baby Signs. The child has been evaluated for hearing loss and does not have any hearing loss and as far as the doctors are concerned, there’s no other medical reason why the baby does not talk.

All that being said, I do want to say that I do not believe for one second that sign language aka ASL impedes deaf/hh children’s verbal language. I think it’s hogwash.

If I was raised by culturally deaf parents who do not speak well and was exposed to sign language from day one and YET am able to speak fluently without any indication of a deaf voice, it shows that sign language do not impede one’s ability to speak, that is, if one truly has enough hearing to be able to hear one speak and has proper speech therapy growing up (as I did). In addition, there are deaf folks with no residual hearing who do speak well and that’s an amazing feat.

This is where I am of the opinion that kids with CI can have AVT and use sign language during periods where AVT isn’t happening, does not impede one’s ability to speak. This is based on my own personal experience (sans the AVT) and if it’s possible with me, then it is possible for others.

I do not see anywhere in the abstract where it says that sign language affects verbal language.

I think this should serve as a reminder that research need to cover evidence that does not leave room to be shot down, that’s all.

Candy, that parent who regretted using baby ASL might be overanxious, or be overlooking a different problem in the child that is yet undiagnosed because ASL is bridging the communication.

It may just be developmental. My younger daughter did not talk till nearly four years old, though she was signing well with her deaf twin brother. Six months in a speech-delayed program turned up the information that she was not speech delayed at all; she simply was a child of few words–answering well when questions were directed at her. Soon after that she was chatting up everybody…one of those inexplicable things children keep surprising us with.


I was thinking the same thing too, the baby will eventually pick up speaking. Some kids are like that, deaf or not. I did not know the parent, and probably will never run into them again…so, I don’t know how the child is doing now.

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Same thing with My daughter’s speech did not pick it up until she can sign to me and deaf friends. I do not agree with their research.. but not want to choose deaf or CODA children.

My daughter, Lilly did not talk until she was 3 yr old. Due to noises around the house and not able to talk. it is not being good kids if they are uneducational with Sign language. it is kind of so different categories were possible untrue valid? It is not true..
I am not support their theory.

I’m jumping in. Amy, thanks for sharing this topic (how may I reach you via email?)

I’d like to share about the longitudinal project I’ve been doing. It’s “Baby Talk in ASL”, “Toddler Talk in ASL” and the next subsequent years. It’s a documentation of the child’s language acquisition in ASL from her birth on a daily basis in a natural native-ASL environment. But, the post is added on a weekly basis at (beginning in January 2012). And “Toddler Talk in ASL” will begin from January 2013.

It’s a bit draft and I’d updated it from time to time when my toddler gives me time (ha!). In the meanwhile, my people, I’d love to receive your inputs via email through that website. I hope we’ll make a difference from our own people’s perspective.

Like David’s comment (When it comes to deaf children, there is a centuries-long “natural experiment”…), I agree — it’s exactly what I perceived. I’ve researched a different side, such as Dr. Petitto, Gallaudet’s VL2, and such along with my own observations.

To date, I have had my thoughts and discussions but that’s something I will bring up later in vlogs when I get enough information from my direct observations along with research.

Off the point, by the way, there are many hearing children (never exposed to ASL or another language) who does NOT vocally speak until age 2 or 3 or so. Then in all sudden, they burst with language development on par with other children’s age. So, we cannot always blame on ASL (if exposed) which may be NOT the factor.

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