Final answer:
Schachter and Singer objected to the James-Lange theory of emotion on the grounds that cognition is not always necessary for the experience of emotion.
Step-by-step explanation:
Schachter and Singer's objection to the James-Lange theory of emotion is that cognition is not always necessary for the experience of emotion. The James-Lange theory proposes that emotions arise from physiological arousal, but Schachter and Singer argued that cognitive appraisal of the situation plays a crucial role in the experience of emotion. They conducted an experiment in which participants were injected with epinephrine and found that the participants' emotional experience varied depending on how they interpreted their physiological arousal.