Timeless demonstrations of Parkinson's first law

"Work expands so as to fill the time available for its completion," Parkinson's law, is an explanation classic that has survived without an artifact-free demonstration at the individual level. To evaluate Parkinson's law, undergraduate subjects expected to judge four sets of photos of faces with reference to a subjective criterion. The experimental subjects, who were told that the fourth set was canceled before they began work on the third set, dallied on the third set; that is, as compared with controls, they prolonged work. The cancellation-dalliance effect was reobtained in two exact replications. It was obtained again in a fourth study, a conceptual replication wherein subjects processed negatively toned phrases against an objective criterion. The generalizability of the effect and explanations for it are discussed.