It may seem that entering writing contests may help you become a more creative writer. However, entering contests could make you more extrinsically motivated. Extrinsic motivation involves being motivated by external factors such as money, awards, and praise. Being extrinsically motivated may undermine your ability to be creative.
In Amabile's (1985) experiment, participants wrote two poems. Before writing the second poem, some of the people were given a questionnaire in which they were asked to rank the importance of some reasons for writing. In one condition, these reasons reflected intrinsic motivation. Intrinsic motivation would involve interest and enjoyment in a creative task. In another condition, these reasons reflected extrinsic motivation. In the control condition, the people did not receive a questionnaire with reasons for writing. On the average, the poems in the control condition were judged to be more creative than the poems in the extrinsic-orientation condition. There was no statistically significant diffenence between the control condition and the intrinsic-orientation condition with respect to judged creativity.
These findings have important practical implications. Being motivated by external factors could reduce one's ability to be creative. It would be better to be motivated by intrinsic factors (e.g. being interested in the task).
References
Amabile, T. M. (1985). Motivation and creativity: Effects of motivational
orientation on creative writers. Journal of Personality and Social
Psychology, 48, 393-399.