Hypothetical priority levels in three experiments.

Pref:D and Pref:E correspond with ‘driving’ and ‘equal’ preferences, respectively. The preference distribution in Experiment 2 is based on Experiments 1 and 3. Arrows (1,2,4,5,7) correspond with differences in priority allocation as result of preference. Arrows (3,6) indicate differences as result of priority instruction, averaged over the number of preferences within each instruction. Dashed arrows point to the weighted average of preferences within an instruction. Numbered arrows are described in the text.