Expectancy-Value Theory explains motivation through an individual’s self-efficacy beliefs. Self-efficacy is one’s beliefs on their capacity to perform a course of action successfully. Self-efficacy beliefs develop depending on different components of life experiences. These experiences are a personal history of success or failure, social messages, role models (vicarious learning), and personal feelings and reflections. It is important to note that self-efficacy is context-dependent and the level of self-efficacy can change across situations. According to the Expectancy-Value Theory, people put more effort into tasks if they believe and almost certain that they are capable of accomplishing it. Otherwise, they tend to doubt their competence and thus tend to not put much effort into it.
Turning to Sheldon, it seems that his self-efficacy was quite stable on physics overtime. Considering Sheldon’s good relationship with physics throughout his school journey, his self-efficacy was fed by his prior accomplishment along with his interest in science. We cannot make sure if Sheldon had a role model, but Einstein, the physicists, might have inspired him to become one. Sheldon's enjoyment and satisfaction in physics-related problems might be considered as physiological feedback that boosts his self-efficacy beliefs.
We see Sheldon’s avoidance of social activities. This might prove the fact that he did not believe his self-efficiency in social relationships. Accordingly, he avoided starting close relationships although he had overcome this obstacle by putting effort into improving his interpersonal skills. Later in the TV show, Sheldon started a new hobby, becoming a YouTuber through his channel called “Fun with flags” to contribute his social skills. But he was not able to become popular, which added so much fun to the TV show. This might be a great example to ungeneralizable nature of self-efficacy. His orientations to master different skills might be an indication that he generally feels self-efficacious. Yet, his less of competence in becoming a decent YouTuber proves the point that he was not self-efficient in becoming a good one! Yet, his self-efficacy on physics led him to reach his goal on becoming a respected physicist, which had come true in the end!