Saying "Children aren't born smart" is equivalent to saying "Intelligence is determined entirely by one's environment", if I understand the claim correctly. While I'm sure talking to ones children contributes in a massively positive way to their IQ, I think it's extremely inaccurate and ignorant to the existence of real-world outliers to claim that it's the only factor.
To provide just one example (out of many, I'm sure): I was born into a very poor (far below poverty level) working class family that was extremely techno-phobic. Despite being actively discouraged almost throughout my childhood of pursuing an intellectual career, I always had an intrinsic motivation and desire to learn and create tech-related things. This ultimately lead to where I am now, as a software engineer (and I'm definitely the only one like this from my family, a clear outlier).
To this day I can't come up with a single environmental influence that explains this -- and believe me, I've tried. I don't mean for this example to detract from the positive message of the article -- that talking to children is very beneficial to their cognitive development (obviously) -- but hopefully to demonstrate that it's a lot more complex than just environmental factors.
To provide just one example (out of many, I'm sure): I was born into a very poor (far below poverty level) working class family that was extremely techno-phobic. Despite being actively discouraged almost throughout my childhood of pursuing an intellectual career, I always had an intrinsic motivation and desire to learn and create tech-related things. This ultimately lead to where I am now, as a software engineer (and I'm definitely the only one like this from my family, a clear outlier).
To this day I can't come up with a single environmental influence that explains this -- and believe me, I've tried. I don't mean for this example to detract from the positive message of the article -- that talking to children is very beneficial to their cognitive development (obviously) -- but hopefully to demonstrate that it's a lot more complex than just environmental factors.