If the Polgar's experiment is so accurate then, then it should be eminently repeatable across not just chess, but other domains. That is, if it's mainly nuture, not nature, people should be able to create other Polgars, if not Lebrons and Serena Williams and Stephen Hawkings.
If there's one thing that you absolutely do NOT need an experiment to discover, is that starting kids early, while affording them the possibility to become Lebron or Serena or Magnus, does not even remotely guarantee them to be in that category of excellence. If they don't have the talent, nothing you do will even get them close, even with lifelong training with the best teachers.
And do you think training kids with a GM will enable any typical kid to play blindfold chess at age 6? Seriously?!
What you still miss is pretty obvious: it can't be done by an everyday layman.
I will never be able to raise my kids to be geniuses. Why?
Because I have absolutely no idea about pedagogy and child psychology.
I'm no expert in teaching, I have no idea how to teach kids.
Neither do you.
It took two brilliant teacher and actual expert of the field to get the girls where they are.
'People' are not able to create another Polgar or Lebron.
But this particular, very talented and dedicated psychologist was.
And Polgar was never able to replicated his study with any other child, or assist any single other parent to even remotely replicate his results.
If Laszlo Polgar was able to crank out top 10 women GM after top 10 GM using his methods (ok, even ONE other top 10 GM of similar caliber as his kids with similar genetics), it would be more plausible that it was more nuture than nature.
Again, you're simply ignorant.
Please do read up on the subject.
Polgár actually wanted to adopt three different african boys to prove his experiments further, to even prove that gender, race, or parents don't matter as long as there is a capable teacher such as himself; but by that time he built up such a contradictory reputation that they actually didn't let him do it, and forbid him to adopt any children.
Don't believe it, look it up.
Again, I stand by my point.
African kids or not - he was unable to transfer the results of his system of training to any other kid except for those with related DNA (his own). He was clearly smart enough and articulate enough to be able to convey his points and ideas to other parents, yet nobody (and I mean NOBODY) has been able to even remotely achieve a Judit Polgar (nobody has even been able to achieve a quarter of a Judit Polgar player using his methods. I'm no Polgar, but it's pretty clear that no matter how hard I try and train my daughter in chess at age 5, she ain't ever approaching even 1/100th of Judit's ability at age 5.)
Most scientists would say that if you can't replicate your results outside of your own very unique situation, you need to start looking at other reasons why your unique situation worked out. And there are a lot of reasons pointing at genetic gifts in the Polgar girls' case, as there was good documentation of their prodigious chess abilities even at an age where kids can barely benefit from high level coaching. (4-5 year olds are NOT particular disciplined students!)
'People' are not able to create another Polgar or Lebron.
But this particular, very talented and dedicated psychologist was.
Laszlo and his wife were not enough to create three champions by their own. After the girls became much better than their father, Alex Chernin was hired as their trainer- and I think a few others were tried before him.
I know Laszlo from an open tournament in Gyongyos back in 1985- he was escorting the 9 y.o. Judit which was participating in the "B" tournament, and picking a lot of scalps in the evening blitz encounters. Zsuzsa was playing in a GM tournament in Baden-Baden, already top class player. I was surprised when Lazslo told me with confidence that Judit will become the strongest of the 3 sisters. Well, he was right.