From The Progress Principle by Teresa Anabile and Steven Kramer…

For one experiment, we recruited seventy-two creative writers. When they arrived (individually) at the psychology laboratory, they all wrote a brief poem on the topic “Snow” (after all, it was Boston in the winter). We used these poems as a pre-measure of creativity, before we altered the writers’ motivational state. Then we randomly assigned one-third of the writers to the extrinsic motivation condition. We gave them a short “Reasons for Writing” questionnaire that asked them to rank-order seven reasons for being a writer; all of those items, according to previous research, were extrinsic, such as, “You have heard of cases where one best-selling novel or collection of poems has made the author financially secure.” The rank-ordering was irrelevant; the point was to have these writers spend a few minutes getting into an extrinsically motivated frame of mind. One-third of the writers filled out a “Reasons for Writing” questionnaire that had only intrinsic reasons, such as, “You enjoy the opportunity for self-expression.” The final third of writers (the control group) spent a few minutes reading an irrelevant story.

Then all of the writers wrote a second short poem on “Laughter.” After all seventy-two writers had participated, a different group of twelve writers independently judged the creativity levels of all poems (without knowing which had been produced by whom). The results were simple and clear. Although the pre-measure poems showed no differences, the set of poems produced by writers who had contemplated extrinsic reasons for writing were significantly lower in creativity than the others. In other words, intrinsic motivation was more conducive to creativity than extrinsic motivation. (Amabile and Kramer 945 of 4705)

The identification is from my Kindle.

Intrinsic motivation makes you more creative.