Final answer:
The experience described in the question can be explained by the Schachter-Singer two-factor theory of emotion.
Step-by-step explanation:
The experience described in the question is best explained by the Schachter-Singer two-factor theory of emotion. According to this theory, emotions are composed of two factors: physiological arousal and cognitive interpretation. In this case, when your mother told you to 'turn that frown upside down,' it changed your cognitive evaluation of the situation and influenced how you interpreted your physiological arousal. By turning your frown into a smile, you changed your cognitive interpretation and thereby changed your emotional experience.