Shamelessly stealing this post from reddit because it's a really cool story:
Context - László Polgár, a Hungarian educational psychologist, conducted an experiment to prove that exceptional talent is developed through intensive education and training, not innate ability. He believed in his theory so strongly that he sought a partner willing to raise children under this philosophy. Polgár wrote to Klára, a Ukrainian teacher, explaining his ideas and proposing marriage as a collaboration in this experiment. Intrigued, Klára agreed, and they married, later raising their three daughters—Susan, Sofia, and Judit—as chess prodigies. From a young age, the girls were immersed in chess and rigorous intellectual training The experiment was a success: all three became world-class chess players, with Judit Polgár widely regarded as the greatest female chess player in history.
- Posted here by /u/heroking4
One other thing that he helped prove is that his children had the same general development curve compared to other children when trained on a subject. Just offset for the early start.
Hence he didn't raise prodigies, as he tried to prove, but rather proved the effectiveness of training/education.