It is not possible, in any science, to perform a study that will prove a theory. The laws of nature maintain order in the universe. Unlike other sciences, social psychology yields only probabilistic predictions. One of the major problems with many current social psychological theories is that important variables are not operationalized in the central theoretical statements. Theories are not provable, but they are disprovable.
Applied research is more valuable in the long run than basic research.
Theory construction can be a highly creative endeavor.