A primary debate in sport psychology is whether sport participation works to form an individual's or if people that acquire specific personality traits are drawn to certain sports and the primary goal of my study is to make progress in answering the question of "can the personality profile of athletes in one sport be reliably different from those in another sport" and also to look at the connection between temperament and personality and their stability throughout one's life. This study involves two phases to measure these differences. the first phase investigated the personality differences regarding the "Big Five Theory" of personality using the NEO-PI-R, a personality inventory. The second phase examined the stability of three temperament dimensions in relation to their related personality factors. Parents of my participants were contacted and asked to respectively fill out the IBQ-R regarding the child's first year of birth. Findings show that team and individual sport athletes have relatively similar mean scores for all five of the personality factors but this data is insignificant. Others findings portray no statistical significance between the effects of exposure to sports and temperament on personality, but the graphs generated from the ANOVAs suggest that exposure is more of a predictor of personality than temperament. Although my results are all insignificant due to the small number of participants, they suggest that exposure to sports (environmental factor) has more effect on shaping personality than temperament (biological factor) does. My research provides support for many theories that suggest environment plays a significant and essential role in the development of personality.