This rating exercise was based on an actual experiment conducted by David Hamilton and Robert Gifford.

In their experiment and in this exercise, Group A had twice as many members as Group B, but the ratio of desirable behaviors to undesirable behaviors was exactly the same in both groups—about twice as many desirable behaviors as undesirable behaviors.

Despite the fact that Group A members performed undesirable behaviors in exactly the same proportion as Group B members, the students in the Hamilton & Gifford study overestimated the number of undesirable behaviors exhibited by Group B members.

Did your results show the same pattern?