Elaborating the differential in differential psychology

The methods of differential psychology have contributed importantly to the current state of behavioral science, but their limitations continue to be well - publicized in the "experimental versus correlational" literature. The argument developed here is that the value of these methods has been constrained as much by the phenomena to which they are applied as by underlying flaws that render them inferior to classical experimental methods. Some applications of differential methods to alternative phenomena are examined that promise to broaden significantly the contribution that differential methods can make to our understanding of behavior and behavior change.