To some extent, intrinsic motivation resides in a person’s own personal- ity.̂ Some people are more strongly driven than others by the enjoyment and sense of challenge in their work. For example, Pablo Casals was driven by pas- sion for the cello from the day he first heard the instrument played: “I had never heard such a beautiful sound before. A radiance filled me. I said, ‘Father, that is the most wonderful instrument I have ever heard. That is what I want to play.'”^ The novelist John Irving, in explaining his motivation to write for up to 14 hours in a single day, said, “The unspoken factor is love. The reason I can work so hard at my writing is that it’s not work for me.”^
Although part of intrinsic motivation depends on personality, a person’s social environment can have a significant effect on that person’s level of intrinsic motivation at any point in time; the level of intrinsic motivation can, in turn, have a significant effect on that person’s creativity. Einstein described the damp- ening effect of a militaristic classroom environment on his own intrinsic motiva- tion when he said,