Subjects’ ability to use functional rules

Ss’ ability to assign numbers to lines according to four different rules—positive linear (PL), negative linear (NL), U-shaped (U), and inversely U-shaped (ITJ)—was studied. The Ss were found to be more skilled in using the PL rule than all other rules and more skilled in using the NL rule than the two nonlinear rules. Implications of these results for functional and correlational learning, as well as for psychophysics, are discussed.