Research continues to point to integration as the higher level competency over simplifying to creativity only. Integration means linking and leveraging the polarities of creativity and analysis, long and short term, familiarity and discontinuity. Some people call this whole brain thinking and as it turns out high performers and people who innovate successfully are whole brain integrators.
There haven't been sufficient studies to definitively uncover the rich mix of nature and nurture that fostered mind integration in these people. What we know is that many of them didn't get there through degrees, training and motivational speeches.
My experience of people observed growing into whole brain thinkers and doers is that it was a rich pastiche of freedom, creative networks, serendipity, boundless curiosity and exposure to a rich world of possibilities that contributed to their development. This leads me to wonder if people at any age and any background can unleash their potentials for whole brain experience.