Final answer:
The interactional perspective, which considers the influence of both personal traits and situational factors, is the most widely endorsed view of motivation by sport psychologists.
Step-by-step explanation:
The most widely endorsed view of motivation by sport psychologists is the interactional perspective. This viewpoint suggests that motivation results from the interaction between individual and situational factors. To illustrate, an athlete's personal traits such as determination and confidence (trait-centered) might interact with situational factors like the support of a crowd or the significance of the match to produce a motivated state. This idea aligns with psychological theories that emphasize the complex interplay between internal and external determinants of behavior, as discussed by humanistic psychologists like Abraham Maslow and Carl Rogers, who focused on personal growth and self-actualization. The interactional perspective provides a more nuanced understanding of motivation by taking into account the influence of both personal and situational elements.