What makes a hypothetical construct “hypothetical”? Tracing the origins and uses of the ‘hypothetical construct’ concept in psychological science

The “hypothetical construct” has been an important concept in philosophy of science for the past half century. References to the concept date as far back as 1943 (Loomba, 1943). Inconsistencies in the use of the term and the related ‘intervening variable’ concept prompted MacCorquodale and Meehl (1948) to distinguish the two concepts and propose conventions for their employment in psychological discourse. They recommended that ‘hypothetical construct’ designates theoretical concepts that “refer to processes or entities that are not directly observed” and, thus, fail to meet the requirements of intervening variables (p. 104). It is interesting to speculate what makes a hypothetical construct “hypothetical.” The motivation for attaching “hypothetical” to constructs is not always immediately apparent. The aim of this paper is to trace the origins of the expression ‘hypothetical construct’, delineate its employment in psychology, and explore the ontological and epistemological presuppositions that underlie conceptions of hypothetical constructs.