We as adults are always very impressed when talking to a child with a mature speaking tone and vocabulary. Things like “they’re going to go far!”, “start saving for college!” and “they’re just like a little person!” are common to hear in circles of adoring parents commenting on their all-but-grown-up kids. That last comment though, “they’re just like a little person” is almost correct: They ARE a little person, and it’s healthy and constructive to talk to them as such.
While not going so far as to never use baby talk on infants, parents should be mindful that kids learn language by listening to us speak. Our mannerisms, social skills, conversation skills, and vocabulary are just a few things an observant child will pick up on and incorporate into their own speech as they grow. Just like reading a Spanish textbook won’t teach you the ins and outs of conversational Spanish, learning from adults speaking to them like toddlers can never completely teach a child English, or any other language spoken at home.
Whether they express it or not, children are always listening and learning. Experience molds our brain which means it’s constantly rewiring. Kids see us switch from ordinary language to high pitched nonsense when we start speaking to them or other children, they lose the opportunity to talk to us like people and say what they have to say. It’s obvious that it’s a different way of speaking to smaller people, and they may internalize that for later life.
There is a book called The Whole-Brain Child: 12 Revolutionary Strategies to Nurture Your Child’s Developing Mind written by Daniel J. Siegel, M.D. and Tina Payne Bryson, Ph.D which focuses on helping parents and caregivers alike better understand children, respond to difficult situations, and build a foundation for social, emotional, and mental health. It talks about the two types of integration in their whole-brain approach (vertical and horizontal) that cause you to act the way you do. Vertical integration focuses on the higher (mental processes) and lower part of the brain (instinct, gut reactions, survival). Horizontal integration focuses on left-brain logic and right-brain emotion.
The first two whole-brain strategies are: 1) Connect and re-direct and 2) Name it to tame it. Connect and Re-direct focuses on first connecting emotionally and then using logic to teach lessons and discipline. Name it to tame it focuses on helping children tell stories about what is bothering them to better process and understand what happened so they feel more in control of their emotions. Talking to kids when they're having an emotional challenge or interpersonal conflict — "Someone is playing with the toy you wanted, and now you're frustrated" — helps them learn to identify and understand their feelings in a way that vaguely sympathetic-sounding gibberish just doesn't. Hearing "Aw, what happened!?" when they get hurt (probably after walking in one direction and looking in another) doesn't teach a child to not to do that again. Offering help and/or a hug while saying something like, "Are you OK? I saw you bumped into the sofa; it looked like that hurt. It's so important to always look where we're going," does. Using clear language, and talking to them about what's happening to them, helps kids figure out cause and effect, and how to prevent and solve problems.
Adults get heated when someone “speaks to them like a child” because it’s patronizing, and no one likes that: not even children. While kids do sometimes need hard facts or lessons sugarcoated a tad, we don’t necessarily need to talk down to them to express that. Kids have less experience than adults, but it doesn’t make them stupid. Talk to your child like a mini-adult: they’re experiencing the world too and have a lot to say. Listen, just like you would for anyone else.
Siegel, Daniel J., Bryson, Tina Payne. The Whole-Brain Child: 12 Revolutionary Strategies to Nurture Your Child’s Developing Mind. New York City, Bantam Books, 2011.