g-factor theory shows that intelligence test scores are correlated, pointing to general factor of intelligence - the g-factor.
Therefore, the above statement can be derived. obviously, individual difference can and will occur, yet in general - this is supposed to be true.
You can look at several different aspects of this question, with varying degree of controversy:
1) Will a great dancer be a better Mathematician than a mediocre dancer
2) Will a great dancer be a better Mathematician than an average guy
Leading to the question - Will a great dancer be a great Mathematician![]()