My wife and I have two boys: a 3-yr old toddler and an 8-month old infant. The toddler is doing extremely well with all physical/motor and emotional/intellectual/communication aspects.
My 8-month old, physically, is also right where he should be. He's crawling, sits up by himself, is starting to pull himself up on to things (yikes), rolls over, picks stuff up with both hands, etc. No concerns there whatsoever.
We also have a copy of the de facto standard, Baby 411, which cites a whole slew of autism screening questions, and again, absolutely no concerns on the autism front: he makes strong eye contact, enjoys being around us and his older brother, cuddles with stuffed animals, is not "off in his own world", etc. No concerns.
What I am becoming concerned about is his language/communication skills. This is one area where we've seen relatively no development since he was a newborn. On one hand:
- He does squeal and laugh when he's really worked up and happy
- Extremely rarely, we'll get a quick "Ahhh" (vowels only, no consonants)
- He cries when he's upset
- He absolutely can hear (we've tested this thoroughly - sneaking up behind him and making a noise to see if he turns his head, etc.)
- He does seem to respond to his name by making eye contact with us
But, on the other hand:
- He's 8 months old, and not a single consonant sound (not a single "Ba" or "Ga"), etc.
- When we engage him isolated and directly (without our toddler there to disrupt), he just doesn't seem interested in communicating back and forth with us; either that, or he just doesn't "get" that he can try to engage us back; it just doesn't occur to him
Finally, my question:
If you ask the Google Gods "8 month old not babbling when to worry"-and similar queries, you'll get an ocean of blogs and forums of parents with identical stories to ours. And in almost every case they get the same regurgitated/canned responses:
All babies are different and acquire skills at different rates.
Yes, I understand that, but: if my son is still not verbal at, say, 30 years of age, clearly something is wrong. So my point is that, at some point between 8 months and 30 years of age, he'll cross over a barrier where it's no longer acceptable to just chalk his lack of communication up to "All babies are different."
So my question(s) is:
- What is this barrier/when is this point? At what age do you finally worry that he may have some learning disability, or something else going on?
- Once a child crosses over this barrier, what are some concrete/actual causes for lack of communication (when neither autism nor physical/hearing disability are present)?
About 3 weeks after posting this question, my son started babbling and using consonants (of course!). He's now 11 months and jabbers/babbles constantly, says "Da!" when he looks at me, and occassionally acknowledges my wife as "Mom!" (lol). So he's not quite at "Dada/Mama" yet, but I have faith he'll be there soon. I'll post updates to this from time to time as I think it may help other parents.
Our little guy is 18 months old now and is exactly where he should be on the milestone chart (below, under the accepted answer). He barely made a noise for the first 8 - 9 months, then started becoming more and more verbal in his 9th/10th month. And now he's got a repetoire of dozens of words that he says with correct annunciation (more or less) and under the right circumstances. He's even starting to put 2- and 3-word sentences together (I love you, etc.).
All this to say, that we're no longer even remotely worried about him, and I advise any other parents with the same concerns that we had to read through all the answers to this question. The accepted answer was truly the best, but many of the other upvoted answers provided a lot of great guidance and emotional support.