But couldn't some programming be beneficial and some harmful? It just seems like quite an oversimplification to say that all TV is neutral or harmful to develo

But couldn't some programming be beneficial and some harmful? It just seems like quite an oversimplification to say that all TV is neutral or harmful to development. My kid is 15 months and we occasionally play "signing time" sign language training DVDs. She's learned a lot of spoken vocabulary from it, and appears to be in the 99th percentile for language development. She doesn't typically sign anything (except for milk) but the other day I asked her what the sign is for a few things and she actually seems to know them. There is no way to tell for certain, but I credit the signing time videos with giving her a very clear sense of core (verbal and signed) language symbolism. The repetition of words, signs, and pictures has always seemed quite interesting to her, with the less familiar, more abstract words/concepts initially seeming a bit less interesting and subsequently gaining significance as her overall awareness improved. I have noticed on the few occasions when we've had a movie or show on the TV when she's been around that she'll initially pay close attention to it and then after a minute or two begin to stare blankly at it... this is quite the opposite reaction she has to the signing time videos. So to summarize I'm skeptical that it makes sense to generalize too much about the specific age ranges when kids are "ready" for various stimuli. I think that metaphor is stretched too far. Instead, a child will find certain stimuli intensely interesting (including some stuff that may be on a TV). To the extent that the child can conceptualize the structure of the stimulus enough to provoke learning, the stimulus can be considered "good" or beneficial to learning. But the developing brain will also get overwhelmed, so after a certain point even a good stimulus becomes noise and can only lead the child to exert effort to tune it out, which would use up cognitive effort for something without any learning benefit.