The idea that children are digital natives is at best inaccurate and at worst a lie.
It's weird how the glitz and glamour of technology can hypnotize even the sharpest people into believing silly ideas. If someone came out and tried to sell the idea that some children are literacy natives, we would scoff at them because we know that the ability to read and write, like all learning, is constructed from the inside out while interacting with our environment.
And yet, as soon as we start talking about smart phones, tablets, texting and other technologies, we get bamboozled into thinking that digital natives exist.
Children who have access to technology and are encouraged to use it in a playful and informal manner grow up to be adults who feel comfortable and competent around technology.
Children who have little to no access to technology and are discouraged from using it (usually out of fear and ignorance on behalf of the adults) grow up to be adults who feel uncomfortable and incompetent around technology.
All this has nothing to do with their DNA and everything to do with opportunity and affluence.