Okay... I have no idea what article you're talking about BUT...
Giftedness is a brain disorder that kids are born with, it doesn't just come on at age 5 or anything.
I have 3 certifiable geniuses in my family (I'm not, and my son's not... Uncle, cousin, grandfather)... So my measurement stick for normal is a little quirky. In my family reading at age 3 (fluently @3, starting at about age 2, by age 3 it's magic treehouse-black stallion for the normal kids), is just plain normal. Things get noticeable when it's not just reading, but reading, say the Illiad in the original greek. And my family, as far as giftedness goes, barring the 3 genius types... is pretty low on the giftedness scale.
My cousin, for example, as a toddler would unscrew a computer, take it apart, and put it back together. After the first couple goes as it, he had it running MORE efficiently. By 5 he was writing code to create new programs. By 5 he also knew something like 6 computer languages. He learned them as a toddler. He'd completed calculus and was in experimental maths by 2nd grade.
My uncle (not his dad, his uncle as well), had graduated from MIT at 17.
These things that sound sorta 'normal' (the elementary school kid who is coding and doing college level maths, the teenage college grad), because we all know of the Doogie Houser type stories. BUT... They were toddlers at one point. Driving their parents to distraction, the way that special needs kids all do.
LOTS of 3 & 4yo gifted kidsqualify for Mensa.
The same way lots of autistic kids qualify for early intervention.
My son is just normal straight gifted (like autism, giftedness is a spectrum
.. Gifted, Highly Gifted, Profoundly Gufted/Genius level). Did the reading as a toddler thing that normal in my family, latched onto numbers and was doing algebra and applied maths at age 7. NeildeGrasseTyson is one of his heros, and he'll sit for hours talking photons with the grad students up at the UW. (AKA, asking questions that lead to more questions to more questions). He's a totally normal kid who loves spongebob, and skateboarding, and videogames, and getting WAY too much mud in the house. He just also has a brain disorder that causes him to process and store information differently than most people. He's been able to understand almost any kind of number related information he's ever heard, almost instantly, and retain it. And he's LOW on the spectrum.
Giftedness is no more 'caused' by bad parenting than Autism is.
It's a brain disorder that affects how information is processed and stored.
Granted, I'm biased, but believe me... the goal has been to keep info OUT of that head, instead of cramming it in / "hothousing".
While there are definitely idiots who get all snobby/snotting and "hothouse" their kids... those are rarely parents of gifted kids. Most parents of gifted kids are just trying to get through the day without their kids electrocuting themselves (again).