Reddit reviews Baby Sign Language Basics: Early Communication for Hearing Babies and Toddlers, Original Diaper Bag Edition (Hay House Lifestyles)

Ooo, I love getting to share this! So an increasingly common practice in recent history is to teach children to sign for things before they're capable of speech. Especially signs for "No", "Yes", or "More", where the gross motor skill is something the baby is capable of learning long before they have developed the ability to actually articulate sounds more complex than babbling. They'll consistently use the correct signs to discriminate between different things, and there's a whole field of books and flashcards and videos (stuff like this) out there to help parents teach their children. Because the child is able to communicate earlier, it eases some of the complications of them not having words yet.

This is just addressing the 'deliberate' part of your post above, but it's really fascinating because it means that we're allowing kids to communicate before they're normally able to.

And now I'm getting completely off track, but there are a bunch of similar branches of research designed to get kids able to do things before they should be able to do them--think of them as baby hacks if you like. One really cool example I got to see in person but can't for the life of me find a link to is basically a remote controlled car that the baby rides on top of. By moving their hands and legs in certain directions, the child can control the car, and navigate their environment. This is mostly used for kids who have some sort of muscular abnormality, and might miss that important developmental stage where exploration is so vital. But you can also use it with kids who just haven't learned to crawl yet, and even if they're late in developing that skillset, they won't miss out on exploration and the things that develop from exploration.

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