Which research method would best support findings related to the facial-feedback hypothesis?

The facial-feedback hypothesis suggests that facial expressions can influence emotional experiences. Therefore, the most appropriate research method to investigate this hypothesis would be experimental studies that manipulate facial expressions. In this type of research, participants might be instructed to adopt specific facial expressions—such as smiling or frowning—and then report on their emotional state afterwards. This manipulation allows researchers to establish a causal link between the alteration of facial expressions and any resulting changes in emotions, which is central to validating the facial-feedback hypothesis.

Experimental studies provide the ability to control variables and directly test hypotheses through observation and measurement of outcomes. This focus on cause and effect is essential when examining how physiological changes (like facial movements) can affect psychological states (like emotions). Other methods, such as longitudinal studies or cross-sectional surveys, do not provide the same level of control or direct testing of the hypothesis since they primarily observe existing phenomena rather than manipulate conditions to observe outcomes.