I don't watch the show, so I can't comment on the children in question, but my husband is incredibly clever, belongs to MENSA etc, and he is emotionally immature. Or at least, he was. He used to properly strop if things didn't go his way, and nothing is ever his fault, he has been known to slap inanimate objects that he's hurt himself on, because the stupid thing moved, apparently.
He's not so bad anymore, but it was very annoying for a while!
My MIL also made him and sister compete, with the complete expectation that my SIL would fail epically because she's a girl. She wasn't allowed to take exams for private school, she wasn't allowed to apply to join MENSA. I think my MIL hoped she would stay at home forever and look after her. As it was, my SIL got two first class degrees and although she lived at home for years, and only just moved out at 33, she has a job that is more suited to her degrees and interests than my husband.
Don't get me wrong, DH has done very well, but he was expected to. In fact, it was demanded of him. SIL wasn't, but she has anyway.
They're both emotionally wrecked though, although DH is getting better.
Me and my brother on the other hand were told that as long as we did our best, that was all that mattered. My best, academically, was never going to be more than a B grade (or equivalent) and never was but I had a great childhood and I have far more common sense than my entire family in law put together.