Leveling Effect of Coaction on Judgment or Retest Effect?

Summary

To test the reliability of Allport's 1924 finding of a leveling effect of co-action on judgment against the alternative of a retest effect, 80 Ss made two sets of 55 judgments of a series of angles (30 to 60 degrees) using the method of single stimuli. Four conditions were used: Alone-Alone, Together-Alone, Alone-Together, and Together-Together with each set of judgments being made either alone or in the presence of a coacting confederate. A significant retest effect was observed, as Ss used the end categories less in the second set of judgments. The leveling effect was not significant.