The fellowships from the MacArthur Foundation may be called "genius grants" by plebs, but are given to adults who have long since developed their motivation and proven their perseverance, not to children in a formative stage of development including development of motivation and perseverance.
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The fellowships, which have come to be known as “genius grants,” come with a stipend of $625,000 over five years — no strings attached.

“We take ‘no strings’ quite seriously,” said Cecilia A. Conrad, the foundation’s managing director. “They don’t have to report to us. They can use the funds in any way they see fit.”

“We try to reach people who have shown evidence of exceptional creativity but show the potential for more in the future,” she added, “to give individuals the freedom to take some risks, to enable them to do new and exciting things.” Emphasis added.
That being said, it would be interesting to see a 5-year follow-up, "Where are they now?", to see whether the stipends propelled these individuals toward accelerated contribution in their area(s) of expertise, or whether they chose to accept the affirmation of their past accomplishments as a signal to rest on their laurels and avoid the risk of further effort which may or may not eclipse their prior achievements.