Baby talk (or CDS, child-directed speech) helps engage their attention and provides valuable feedback. Kids who experience less CDS develop language more slowly.

See https://en.wikipedia.org/wiki/Baby_talk

(I heard about this research a number of years ago. Although I must admit, now I wonder if it’s affected by the science reproducibility crisis!)

Could just be luck (well, genetics, probably) I guess. Maybe they'd have developed even faster if we'd used baby talk. One shitty thing about parenting is it's really hard to tell what helped, what hurt, and what didn't matter at all.

I would put a lot more of it to having (seemingly) engaged parents. Even a backwards strategy enacted by a loving parent who is consistently trying their best is likely to outperform the result that most can manage (owing to time/money/education/etc).

Genetics are a marginal element approaching none.

Compare a toddler living in a ghetto concrete jungle to one who takes daily strolls through Central Park or Suburbia. The enrichment of parents teaching about the trucks and the trees and the lady with a purple hat pays massive returns.

But, but... I didn't say anything about baby talk!!

The definition in that Wikipedia page is about something completely different: exaggerating intonation.

Fathers descend to "baby talk" when the child is learning and slowly bring them up to par instead of trying to just force perfect talk from the start. They do this instinctively.

There's some great comments on this from salman khan, I think. He recorded the first years of his kid's life at home and documented this phenomenon

The sites that Googs returns are basically the internet's version of googoo gaagaa. I look at the websites returned, and often think that the site's owners must be morons. Useless drivel clearly designed to game the Goog search results. I think think about how moronic it is that Googs allows this.

I suspect they know the sound they want to make but they don't know how to articulate it. They make an approximation and we can encourage them repeating the correct version, so they realize we understood what they're trying to do: "you're half way" but repeating their approximation is misleading.

I subscribe to the theory that this helps babies understand what they sound like, and therefore helps them learn how to produce the sounds they want.

Congratulations on recognizing the true morons.