First, I want to start this off by saying: I do not have children. However, I was once a child, knew other children, know adults that were children and know adults that do have children. So, take my opinion for what it is: an opinion. An opinion based on observation.
One of the biggest disservices you can do for a child is to confuse precociousness with higher than average intelligence. Precociousness is early development, or reaching milestones before peers. Human development takes place at various speeds depending on environment and individual factors like genetics, etc. This is widely accepted as fact. We also know that the rate at which children reach milestones does not necessarily denote intelligence. So, early development does not unequivocally mean that a child is more intelligent than their peers who develop after them. This is so often not how people interpret development rates.
Parents of kids who reach milestones sooner than expected often get into their head that their child is super smart and starts to condition that child to believe they are smarter, and therefore better, than those around them. The child gets an ego and a superiority complex that follows them through childhood into adulthood and then once they are out in the real world, they crumble upon realizing they are not the smartest, most capable or some otherwise irrefutably brilliant person. They are not prepared to be humbled, to be criticized, to be pounded to a moral pulp by the harsh and cruel capitalist society they are a part of, yet have been shielded from.
These adults, who have just had their entire sense of self shattered, become liars and deceivers to keep up the charade that they are exceptional and “not like everyone else,” as if our own individualistic traits and tendencies don’t already prove we are all different from each other. They cannot cope with being “just a normal” human. They have to be smarter, better, more creative, whatever.
I see this in a lot of adults today, online, especially. Nothing about them is particularly remarkable, but they are condescending snobs for no real reason; acting holier-than-thou and just dripping of self-righteousness, desperate to be perceived as amazing. The truth is, these people are just like the rest of us, and while we each possess talents and abilities unique to ourselves, we are, collectively, similar.
